30 August 2007

So long...

...and thanks for all the fish!

Early indications have shown that during June and July, the total number counted of the 3 main dolphin species, Common Dolphin, Striped Dolphin and Bottlenose Dolphin, are down by around 80% on the same time last year. Seabirds, such as auks, shearwaters, and gannets have also been in short supply and the situation has been ongoing since the early spring, with no signs of an improvement thus far during August.
Perhaps they went to Scotland?

29 August 2007

Antarctic Ozone Hole

It's ozone-hole season again, and this year is off with a bang...

A hole in the ozone layer over Antarctica has appeared earlier than usual in 2007, the UN weather agency says.


"It is still too early to give a definitive statement about the development of this year's ozone hole and the degree of ozone loss that will occur. This will, to a large extent, depend on the meteorological conditions," the Geneva-based agency says.

But it says that observations so far could "indicate that the 2007 ozone hole will be relatively small".

The WMO report is here. Their reasoning behind the forecast is that 1.) the polar vortex, while the largest ever, is relatively unstable, and 2.) Hydrochloric acid (HCl) , the chemical species that converts into the ozone-destroying catalyst chlorine oxide (ClO), is nearly depleted near the vortex.

The report suggests that the early start was brought about by the non-circular shape of the vortex

27 August 2007

Greek fires

This summer, Europe has been experiencing unusual weather, to say the least. Extreme heat, drought and unusual fire activity have all been observed. Now comes a weekend of extreme fire, with at least 62 reported dead over the course of the last three days.

Over 170 fires have been burning, overwhelming apparently unprepared fire authorities. Numerous countries, including Australia, are sending aid and volunteers to assist.

The Christian Science Monitor asks the question “Why is Greece on fire?”:

This has been one of the hottest and driest summers in recent history, and much of southern Europe has been plagued by forest fires. In Greece, the dry conditions have played a role. But many of the fires, government and forestry experts say, have been set by arsonists, hoping to clear land for development.

Some reports (see FireFighter Blog) have suggested that the fires are an act of terrorism. I acknowledge the possibility, but find this unlikely. I suspect that this is part of that paranoid thinking that always comes out after events like this. It never pans out, the story just always kinds of fades away...Did people start these fires? Most likely. I don't think it was 'terrorists', though. More likely accidental starts or some lonely pyromaniac-type out trying to impress his imaginary girlfriend...

"Most of the reasons concern changing of land use – from forest to something else [such as] construction, or building, or to grazing, or agriculture," explains Nikos Georgiadis, head forest officer for the Greek office of WWF (the World Wildlife Fund). "But the response from the government has not been effective at all."


Greece has one of the worst records in the European Union on environmental issues, and on forest protection in particular. Environmental groups say recycling is in its infancy, development is largely unregulated, and protected areas neglected.

Regardless of arson and/or land use change, the fires are in no small part down to the particular
weather and climate that has been observed over their summer. Without an appropriate climate 'setup', fires of this magnitude could not occur.

2006 was a climatically unusual year. 2007 is turning out to be even more unusual. Still, single events like this do not constitute 'proof' of global warming. Believe that if you will, but the global nature of the extremes this season suggests that things have changed. Even if you choose not to accept that, this year is certainly a good model year to take as the example for what climate change will be like.

Welcome to the future.

24 August 2007

News flash

“I'd like to be the first to welcome our new jellyfish overlords...”

A worldwide upswing in jellyfish?

So why the increase? Why now? and Why in so many places at once? They are several possible answers, pretty much all human-caused one way or another.

Once answer is climate change as felt through warming ocean temperatures, which creates a more favorable environment for jellyfish and allows them to expand their range.

Another answer is the loss of sea turtles and other jellyfish predators, permitting more jellyfish to survive. The overfishing of species which directly compete with jellyfish for food is another possibility.

Finally, sewage and agricultural runoff adds nitrogen to the water, which jellyfish thrive upon.

A couple of quotes from the Independent article above

"Jellyfish are a natural part of the marine environment, but the scale of what's happening now is a warning that something's going very wrong," says Dr David Santilo, a marine biologist for the Greenpeace research laboratories at Exeter University.

The French-Canadian biologist Daniel Pauly paints an apocalyptic vision of oceans taken over by jellyfish: "We are moving from a marine ecosystem dominated by big fish to a soup of small organisms. If we carry on like this the only things in the sea will be jellyfish and plankton soup."

More unintended consequences of our way of life and notions of progress...

21 August 2007

Karangetang: Will it blow?

A bit off the main topic of this blog, but interesting and relevant nonetheless is this recent news item from Indonesia:

Lava and hot gas clouds from a volcano in eastern Indonesia are threatening more villages, officials said on Tuesday.

...The volcano, on the diving resort island of Siau off Sulawesi and 2,325 km (1,445 miles) northeast of the capital Jakarta, is one of Indonesia's most active volcanoes.

...The alert status on the 1,827 meter (5,994 feet) volcano was raised to maximum at the weekend after hot clouds started moving eastwards, posing a threat to hundreds of people.

Another volcano 175 km (110 miles) south of Mount Karangetang has also been spewing ash and sending debris down its slopes.

But Mount Soputan, which lies on the northern tip of the Sulawesi island, is not yet seen as a threat to nearby villages.

The relevance to climate is the possibility that it might explode with sufficient force to inject aerosol into the stratosphere. A recent example of the climates impacts of volcanic eruptions would be Mt Pinatubo in 1991:

The cloud over the earth [from the eruption] reduced global temperatures. In 1992 and 1993, the average temperature in the Northern Hemisphere was reduced 0.5 to 0.6°C and the entire planet was cooled 0.4 to 0.5°C. The maximum reduction in global temperature occurred in August 1992 with a reduction of 0.73°C. The eruption is believed to have influenced such events as 1993 floods along the Mississippi river and the drought in the Sahel region of Africa. The United States experienced its third coldest and third wettest summer in 77 years during 1992.

The short- and longer-term climate impacts are potentially quite significant. Other 'recent' eruptions with a global climate impact were observed Mt. Agung in 1963 and El Chichon in 1982. How likely is an event of this magnitude from this volcano? (Keeping in mind that I have no specific knowledge in this field, and may not know what I am talking about...)

The eruption history of Karangetang suggests that this is unlikely. The volcano erupts quite often, with small to moderate eruptions. The largest Volcanic Explosivity Index (VEI) from this volcano is 3 (Moderate to Large)**. This table suggests that stratospheric injection is 'Possible'. These events are rare in the history of this volcano, more likely is a 1 or 2. These facts suggest that most likely, this volcano will not have a significant impact on the global climate.

**For comparison with other eruptions, Pinatubo has VEI=6 , and the other two eruptions noted above had VEI=4. Its apparently not all VEI, though. Location is also important in determining the overall climate impact. Tropical eruptions are more efficient at cooling the globe. I would also guess that the amount of ejecta, particularly sulfur dioxide, from the volcano would also play a role.

19 August 2007

Asia: The heat of the moment

Sorry for the cheesy 80s song reference. I couldn't help myself!

Floods have ravaged Asia in 2007.

The floods have left millions homeless in India, Bangladesh and Nepal. But are the rains exceptional, and a product of global warming? Climatologists point out that until the last days of July, this summer's monsoon had been weak, with fears of crop failure due to drought rather than flood. Nevertheless, in general, global warming is adding to river flows by melting the glaciers of the Himalayas.

Several tropical cyclones have been noted, including

Super Typhoon Sepat came ashore in Taiwan on August 17, 2007, after bringing torrential rain and flooding to the Philippines the day before. ... The typhoon was classified as Category Five typhoon...with sustained winds of 184 kilometers per hour (114 miles per hour), according to CNN.

Japan has had a tough season thus far. In July came super-typhoon Man-Yi, the worst storm to hit Japan since records began in 1951. and simultaneously, a large (~7.0) earthquake which damaged a nuclear plant. Now they are having an extended heatwave and difficulty meeting the associated increase in power demand.

None of these individual events can be explicitly shown to have been caused by anthropogenic. They are merely data points in the ongoing sample needed to statistically verify what your senses and your instinct are already telling you—things are changing; the weather is different.

The strongest climate forcings are those produced by humans, including the anthropogenic increase of CO2 from the burning of fossil fuels, other byproducts of our civilization like ozone or other pollution and changes brought about from modifications to the land surface. Recent news items indicate that these are apparent in Asia

Siberia is experiencing earlier springs, a study of satellite images has revealed. The trend is likely to be triggering more forest fires, say researchers, and to be linked to global warming.

Satellite pictures over much of Asia and the Indian Ocean show an enormous brown stain hanging in the air - an unwanted byproduct of rapid economic growth which is having a curious effect on climate change and is affecting Australia.

Named The Asian Brown Cloud, it is made up of pollutants from woodfires, cars and factories, and scientists now believe it to be the reason glaciers in the Himalayas are melting.

A study...at the CSIRO recently suggested that the Asian haze might be actually increasing the rainfall in tropical Australia by changing the balance of temperature and circulation between Asia and Australia,"

This last item brings another facet to the manipulations in the cryosphere, another potential source of glacial melting. I've seen seminars regarding the Brown Cloud research. It is one possible link to the increased rainfall over NW Australia, particularly in summer. The basic idea is that the cooling in the pollution cloud displaces the region where the 'thermal equator' or ITCZ lies, changing the rainfall patterns on quite a broad scale.

CO2 forcing is real. Land-surface forcing is real. Regardless of the dominant mechanism at any given locale, the changes are primarily human induced. The solution is similar for either problem: live in an environmentally sustainable manner.

17 August 2007

Australian Edition

Some climate-related impacts and observations from Down Under, the land 'girt by sea'...

    Australia's 2005 emissions totalled 559.1 million tonnes of carbon dioxide equivalent (Mt CO2-e), the government's Greenhouse Office estimates. This accounted for around 1.5 percent of total world emissions.

    Australia is the world's top greenhouse gas emitter per capita because of its reliance on burning coal to generate electricity. Per-capita emissions fell 14.4 percent between 1990 and 2005, from 32.3 to 27.6 tonnes CO2-e, the Greenhouse Office says. But current per-capita totals are still double the industrialised average of just under 13 tonnes.

So while Aust's total emissions aren't large by percentage, we punch well above our weight, being the leading emitters on a per capita basis. We are using well more than our share. This is one area where we could (and should!) show some global leadership. It is shameful that we are not part of the Kyoto Protocol, whatever merits it does or doesn't have. It suggests that we are not serious about tackling these issues; we are part of the problem, not part of the solution.

Australia is already experiencing human-induced climate change impacts. Multi-year deficiencies of rainfall in many regions. The effects of these recent droughts is exacerbated by climate change – warmer temperatures lead to more evaporation and drier conditions. As a result of these droughts, along with population growth, there is not enough water to support most of the major cities. New water sources are needed in 5-10 years.

In the Torres Strait Islands, there is too much water. The islands are sinking, a result of rising seas resulting from global warming. There have been recent floods in Tasmania, as well as in Gippsland (eastern Victoria) and across coastal New South Wales earlier this winter.

There is also evidence to suggest that our land use choices are affecting the climate. This articles seems a bit strange for some reason. It is not clear why they are interviewing the people they are. This has been studied in Australia as well...

The rabbit-proof fence ... acts as a boundary separating native vegetation from farmland.... [A]bove the native vegetation, the sky is rich in rain-producing clouds. But the sky on the farmland side is clear.


Within the last few decades, about 32 million acres of native vegetation have been converted to croplands west of the bunny fence. On the agricultural side of the fence, rainfall has been reduced by 20 percent since the 1970s.

[A scientific aside: Three hypotheses for this behaviour are related in the item. Only the third idea makes any amount of physical sense. The researchers (and/or the reporter!) are failing to consider the differences in surface moisture flux surface from the different vegetation types. I would expect warmer, drier surfaces with deeper boundary layers over the agricultural land (except perhaps after irrigation)]

Are these events related to anthropogenic CO2 enhancement? That there is a CO2 forcing is undeniable. I mean, of course increasing the CO2 concentration is going to have a radiative effect on the planet. Its not a big conceptual leap to associate the increased forcing and the observed changes. How large of a role do land-use changes play? Its has been observed that cities affect their weather. Irrigated fields do the same (but not forever...). There is a two-way interaction between the land surface and the (micro-)climate of a region. It is a mistake to consider the two sources of change mutually exclusive.

This is an issue cutting across science, policy and society; rightfully the subject of ongoing debate. It must be addressed in order to understand, predict and plan for the impacts of human-induced environmental change. Taking steps as a society to minimize our environmental impact --even something as simple as energy conservation -- is a good start. Phasing out incandescent bulbs is a nice gimmick, but it will take more than that to fix our mess. Even if we only emit a small amount of the global total, it's better for us to accept the responsibility and lead by example. No more 'stamping our feet', getting angry with denial and lies about the climate and our culpability.

16 August 2007

Polar heat

Lots of things happening up in the Arctic. Big changes are afoot, in both the planet and in our politics and these are manifesting themselves there. Climate change is reducing the amount of sea ice and consequently opening opportunities for access to new territory and resources.

First, the melting ice. From the National Snow and Ice Data Center:

Sea ice extent is currently tracking at 5.4 million square kilometers (2.1 million square miles), with daily extents running at 940,000 square kilometers (361,000 square miles) below previous daily record lows, a significant decline from past years.

The image shows the extent of sea ice compared to the median position. The ice is quite shrunken on the Alaska-Russia side of the Arctic. The Figures 3 and 4 on the page show the high pressure and warm temperatures which are manifest over the area. In general, the last several years have been generally warmer than average over Alaska. There was quite extensive wildfire activity there in 2004, indicative of the heat. That is certainly broadly consistent with the idea of global warming and climate change. It could also be associated with interdecadal variability.

Some problems with melting ice in the north include the threat to polar bears, the migration of so-called pest species and the introduction of new insects and disease into the region. For more discussion of possible impacts, see here.

When trying to understand and predict what is happening, we should remember that we have never observed (with contemporary observations and theory) climate change of this magnitude. We can't predict either what will happen or how it will happen with any certainty or detail. Our climate models can only give us a broad picture of what will happen. The history of science suggests that we should expect surprises and new insights. We usually do when we make new observations.

On the geopolitical side of things, tension is building over a new 'land rush' for the North Pole. (Sorry, haven't saved the links here...) Russia made a claim by planting a little metal flag on the sea floor at the pole. The US and Canada have responded, indicating that such a claim is not likely to stand. Denmark is also staking a claim, acting through Greenland (which it controls), who rightfully have interests in the area.

That governments are responding to the issue should indicate the seriousness of the problems facing humanity, including climate change and peak oil. If the governments are moving on an issue, even the most hardcore skeptics must see that there is something to it. Rather than basing their judgments on ideology, they are using an honest assessment of the facts and acting on a forward thinking strategy. As a society we should move towards adopting a similar mindset, as planning and forethought are the only ways out of our mess.

13 August 2007

It's going to take more...

...than simply planting trees. Planting trees is nice, and it should continue (in a sensible, environmentally-sound way). However, new research suggests that trees aren't going to help as much as we previously believed. This is seen in both the tropics and in mid-latitude areas.

Data collected on forests in Panama and Malaysia has revealed that global warming could reduce the growth of trees in tropical rainforests by 50 percent, besides severely affecting their ability to remove carbon dioxide from the air.

While 10 years of bathing North Carolina pine tree stands with extra carbon dioxide did allow the trees to grow more tissue, only those pines receiving the most water and nutrients were able to store significant amounts of carbon that could offset the effects of global warming,

The gist of both of these items is that trees aren't as effective at storing CO2 as hoped. Vegetation doesn't show a simple linear relation whereby enhanced CO2 leads to more tree growth for ever and ever. There is a limit, which could easily be reached sooner rather than later. Maybe we can push it, as observed in the second item

In order to actually have an effect on the atmospheric concentration of CO2, the results suggest a future need to fertilize vast areas," Oren added. "And the impact on water quality of fertilizing large areas will be intolerable to society. Water is already a scarce resource

I would think that it is not just water quality, but also nutrient runoff from the fertilizer creating algal blooms in the ocean. These blooms can lead to 'dead zones' like those recently observed off the Oregon coast and in the Gulf of Mexico. More of humanity's hubris.

In a bit of apparently good news

Deforestation of the Amazon rain forest in Brazil fell by about a third in the 12 months through July to the lowest rate in at least seven years, the government said on Friday.

An estimated 9,600 square km (3,707 sq miles) of the world's largest rain forest were cleared in the year ended July 31, compared to a revised 14,039 sq km (5,417 sq miles) the previous year, the environment ministry said.

Any progress is good, but losing a million or so hectares a year is still a lot; it was considered problematic 7 years ago when last that low.

A better idea is consider attacking the root cause -- the wasteful, consumptive nature of western society – rather than attempting another in a series of house-of-cards technological quick fixes. Tree planting and other measures are important for mitigation of climate change, they are just not the whole story. In closing, consider this thought from the blog Climate Frog:

One thing we don't want is for people to be sold on taking actions that do little to change the trend toward climate change while offering them a feeling of complacency that, "Now I've done something to help. I can relax now."

12 August 2007

Decadal-scale forecasting

Here's more on the decadal forecasting scheme I posted earlier. I think that was the first one that came across the feed, and it not especially clearly written...It was very late, too

Anyway, Nature News has the best report I've seen so far (I have to wait to read the paper...we get Science a few weeks late in the library for whatever reason...). I really like the accompanying graphic, reproduced here. To my mind, the graphic alone raises all sorts of questions and thoughts. More on that below, on to the story

British researchers have substantially improved the performance of a global climate model by adding observations about the actual state of the ocean and atmosphere. The results are of seminal importance for those trying to produce reliable short-term 'climate forecasts' on global and regional scales, experts say.

The team, led by Doug Smith of the UK Met Office's Hadley Centre in Exeter, has developed a climate prediction system that is capable of including natural variability in the climate system — such as that arising from anomalies in ocean circulation or ocean heat content — into modelling carried out by a global climate model...

I would think that there is small (but finite) chance the model follows that consensus forecast path. I suppose it really depends on what the ocean does and how well the model reflects that reality. That especially presumes there will not be some major, new climate forcing like a major volcanic eruption, an asteroid strike or a regional nuclear war (If there is a global nuclear war, the forecast doesn't really matter...) to throw the climate completely off-track.

[On a bit of a speculative tangent: I find the behaviour of the global temperature in the post-Pinatubo period quite intriguing. The focus of volcanoes and climate seems primarily on the immediate cooling. We see that cooling here. As this post-eruption cooling fades, the result is what appears to be an amplifying oscillation, which culminates in the 1997-8 El Nino event. Are the two things related? Perhaps conincidentally, the similarly huge 1982-3 El Nino also closely follwed a major volcanic eruption...]

If the model is correct, in the next few years natural variability — mainly in factors affecting the heat content of the ocean — will offset some of the climate warming resulting from humanity's greenhouse emissions. But global warming will be taking only a brief breather: half the years from 2009 to 2014 will be warmer than 1998, which is currently the warmest year on record.

Again, I can;t really see the predictions being correct in anything but a broad sense...it's going to get warmer by so much by some time

This prediction is still rather tentative, though. While setting up the initial conditions helps, the various inherent difficulties in the model's attempts to capture all the processes going on mean that the system's forecasts will be far from perfect. The predicted temperatures carry healthy error bars, but Smith points out that the flattening it foresaw in the first few years seems so far to be accurate.

I think this guy sums it up pretty well...

"This study is not primarily important for the brave temperature prediction it makes," he says. "The key thing is that we now have a convincing concept for combining observations and models. It may not be the last word, but it does prove that concrete decadal predictions are possible."

Another area of interest: How is this going to be used for, say, future public planning? Someone, somewhere (justifiably) is going to want to do something along those lines. How do these predictions get turned into useful proposals/actions? What happens when the prediction goes wrong (or at least different)? Who gets blamed in our litigious society?

10 August 2007

A brave climate forecast

I don't know any of the relevant details, but this looks to be a mighty brave forecast. I hope it fails miserably, not due to hard feelings or anything, but because I would prefer not to live through the consequences!

Scientists predict surge in global warming after 2009 -- ABC News

A study forecasts that global warming will set in with a vengeance after 2009, with at least half of the five following years expected to be hotter than 1998, which was the warmest year on record.

09 August 2007

Agriculture and climate change: A two-way interaction

Agriculture – farming, grazing and the tending of orchards, vineyards and timberland – is one of humanity's greatest achievements. Its development around 10 000 years ago set the stage for our current civilization. Having a steady source of food aided in both our sociological and technological development. The vagaries of weather and climate have always been a threat to agriculture at any given time. Climate change presents an even greater danger. Even absent a changing climate bring more extreme weather, the signs are troubling.

Some people worry about peak oil. I worry more about peak grain.

The fact is that world per capita cereal production has already passed its peak, which was back in the mid-Eighties, not least because of collapsing production in the former Soviet Union and sub-Saharan Africa. Simultaneously, however, rising incomes in Asia are causing a surge in worldwide food demand.

Already the symptoms of the coming food shortage are detectable. The International Monetary Fund recorded a 23 per cent rise in world food prices during the last 18 months. Maybe you've observed it yourself. I certainly have.

Of course, we're not supposed to notice that prices are going up. In the United States, the monetary authorities insist that we should focus on the "core" Consumer Price Index, which excludes the cost of food. According to that measure, the annual inflation rate in the US is just 2.2 per cent. But food inflation is roughly double that.

However, the spectre of climate change adds a new challenge.

Climate change with frequent droughts and floods is likely to cut food output and increase hunger risk in developing countries, the U.N food agency said on Tuesday, adding its voice to global warming concerns.

Even small global temperature rises would trigger crop declines and raise the risk of hunger at lower latitudes, especially in the seasonally dry tropics, said Jacques Diouf, director general of Food and Agriculture Organization (FAO).

"Rain-fed agriculture in marginal areas in semi-arid and sub-humid regions is mostly at risk," Diouf said in a statement after a conference in India.

"India could lose 125 million tonnes of its rain-fed cereal production -- equivalent to 18 percent of its total production," he said.

Flooding and other extreme weather, attributed to climate change by the World Meteorological Organization, has reached new heights thus far in 2007 (see here and just about any of the other posts on planet doom?). Global warming is already beginning to detrimentally affect agriculture worldwide. For example:

Meeting the future demands required of agriculture requires careful planning.

Growing food and fiber entails the use of fertilizer and irrigation systems and results in land clearing. These 'side effects' of agriculture can lead to regime shifts--or 'tipping points' which include desertification, salinisation, water degradation, and changes in climate due to altered water flows from land to atmosphere.

As human populations shift to more meat-heavy diets, trade of agricultural products increases, and demand for biofuels grows, the pressure on agricultural systems is mounting. The challenge is to figure out how to meet these demands and keep the ecosystem functions that underpin productivity working

[...T]he mid-United States, the Amazon, the Sahel, India, and Northern China [are] the most likely areas to undergo climate change...

[...L]and use changes [are equivalent] to fuel emissions in their potential to drive climatic changes...local land cover changes may very likely generate changes elsewhere by altering the general circulation of the atmosphere.

There are potential solutions, though...

The development of cropping systems resilient to extreme climatic conditions is a major challenge to farmers. USDA researchers have summarized their findings on the short-term effects of a variety of crop sequences in dynamic cropping systems.

Around the world, extreme climatic conditions are forcing farmers to rethink current cropping system strategies. To maximize crop production in the face of variable temperatures and precipitation, scientists say farmers may want to adopt a system in which crop sequencing decisions are based upon weather patterns and management goals each year. However, before making the change to a more adaptable cropping systems strategy, researchers say it’s important to understand how short-term crop sequencing decisions affect key agronomic and environmental attributes.

The impact of climate change on agriculture presents a serious threat. It is real, and is already beginning to be felt in many areas of the world. Careful planning and cooperation is required. Rash actions in land management could make the situation worse.

Afterword: For more on land use impacts and climate change, I recommend Roger Pielke Sr's blog, Climate Science. Though known as a skeptic's site, the main thrust isn't so much denial as it is the understated importance of land use changes on the climate.

07 August 2007

Hurricane debate continues

In following on from my post of 31 July, More hurricanes, anyone?, on the recently published Holland/Webster paper on Atlantic TC trends, I point you towards this item on Roger Pielke Sr's Climate Science blog.

The post takes a closer look at the data issues involved in creating the long time series record used to estimate the trends. The basic conclusion?

Landsea was absolutely correct about the sloppiness, which is inexcusable. The jury is still out on trends, though uncertainty seems sure to persist for a while, despite the loud and aggressive claims to the contrary.
My take is still that both sides are correct to some degree. The upswing in storms in recent times is real and not too negatively influenced by data problems. The data in the earlier era undoubtedly underestimates the number of storms. This post points out several shortcoming in the Holland/Webster analysis methodology, increasing the uncertainty of the magnitude of any trend that may exist. The number of storms likely hasn't doubled in 100 years, but some trend is still likely there.

I suppose we will have to wait another 10-20 years before we truly know the magnitude of any trend and whether anthropogenic climate change is influencing hurricane numbers...

06 August 2007

An interesting question

From Climate Progress

Did Climate Change Contribute To The Minneapolis Bridge Collapse?

Those who argue against strong action today to reduce greenhouse gas emissions — the adapters who are essentially saying to climate change, “Bring it on!” — cannot criticize those who then ask the obvious adaptation question — how will climate change impact this country and its infrastructure?

Certainly climate change will have the biggest infrastructure impact on our coastal cities, water and sewage systems, levees, and electric grid. But given that a remarkable 70,000 other bridges in the country are also structurally deficient, we should seek to learn whether such troubled bridges can take the ever-growing stresses generated by global warming.

IPCC Working Group II report

The latest full report of IPCC Working Group II, focusing on impacts, adaptation and vulnerability is now available. Here is the link.

The wave of the future

A study was published in JGR Atmospheres this week entitled “Doubled length of western European summer heat waves since 1880”. While I haven't read the paper, there have been several 'popular science'-type stories which give many of the salient details. For example (also, here and here):

The most accurate measures of European daily temperatures ever indicate that the length of heat waves on the continent has doubled and the frequency of extremely hot days has nearly tripled in the past century. The new data shows that many previous assessments of daily summer temperature change underestimated heat wave events in western Europe by approximately 30 percent.

From a science perspective, an important point is that these data have been homogenized, that is, they have had the artificial trends and discontinuities associated with observational practices, instrumentation changes and such identified and corrected, giving a more accurate estimate of the longer-term behaviour of the time series.

I would suspect that these findings reinforce the notion that the heat over SE Europe can be regarded as an impact of climate change. The map, from IRI at Columbia University, shows temperature anomalies over the past three months (May, June and July) over Europe. Anomalies of 2C are seen across much of southern Europe, from Italy to points east. Peak anomalies of over 3 C were observed in Romania.

The impacts have been enormous. Here are a few with representative links:

If we act now, reduce our emissions and move towards a sustainable lifestyle and economy, then this is our future. If not, things will likely get worse, with more heat waves, droughts, floods and fires. It's our choice.

05 August 2007

GRL paper on climate shifts

This post is a diversion from the usual subject of this blog into the more technical aspects of climate change and global warming. I do this in reaction to a recently published paper in Geophysical Research Letters: A new dynamical mechanism for major climate shifts by Tsonis et al. The press release which announced this paper is here (which is also how my attention was drawn to it).

There have been blog reactions to this (for example, here and here). Most of them are by skeptics and Deniers who claim that this is somehow 'proof' that CO2 has no effect on radiative transfer in the atmosphere and does not cause global warming or some such nonsense. Perhaps, when reading the somewhat misleading press release you can parse those words to mean something like that. However, reading the actual paper (always the authoritative source!) tells a different story.

To begin, the authors of the paper are not addressing the issue of anthropogenic climate change, but rather that of interdecadal variability. They aren't the same thing. No vaguely respectable climate scientist would say that there is not interdecadal variability, and it is certainly a possible explanation for some of the observed warming in recent decades. Nobody has claimed otherwise, including the IPCC. Unfortunately as interdecadal variability is something that is poorly understood at this time, the uncertainty is likely to remain.

Second, the paper does show some interesting shifts in the observations of the global temperature trends in the early 1910s, the early 1940s and in the mid-70s. The correspond with the 'synchronization' of the behaviour of some of the primary modes of climate variability, the main thrust of the paper. Between 1910 and 1940, the temperature increases. From the 40s to the 70s, the trend is around zero, or even slightly negative. It again begins to increase from then until now. The timings of the synchronization and the trend changes are very close, which provides strong evidence in favor of their hypothesis.

The authors then use 'state-of-the-art' climate model to see if they can detect similar signals there. Two simulations are used: one with constant pre-industrial CO2 levels, the other a business-as-usual 21st century simulation. The vertical axes on the plots are a bit misleading (they change between observations and simulations...), but the models show an effect that is much smaller than seen in the observations by at least a factor of 2. Also noted in the text: the authors removed a 2oC/century trend due to radiative effects in the 21st century simulation for clarity in the figures. This radiative trend would swamp the relatively small signal of the natural climate shift.

All in all, the paper provides a nice hypothesis for understanding the mechanisms of natural interdecadal climate variability, but the work is far from complete. For instance, there is no discussion of what it means physically when the indices synchronize. Can we observe it as it happens, or is it something that can only be determined after the fact? However, this hypothesis in no way refutes or invalidates the hypothesis of anthropogenic climate change through CO2, nor do the authors intend to do so. Here is the closing line from the paper:

...the climate shifted after the 1970s event to a different state of a warmer climate, which may be superimposed on an anthropogenic warming trend.

I think that is a pretty clear statement of the authors meaning.

02 August 2007


Humans, as a species, are control freaks; we seek to establish complete dominion over our environment. In our selfish arrogance, we often fail to anticipate the consequences of our actions. Denial that there even are problems is common; assumptions of human mastery over all is a given. This attitude is apparent in our approach to dealing with both weather issues and climate change.

For instance, we see this whenever a drought occurs. The cries arise for cloud seeding, a vain attempt at producing or enhancing precipitation. Despite being pursued for well over half a century, whether it actually produces the desired results in still unclear. It does leave measurable, physical effects on the cloud, but it is not clear that it enhances precipitation. If so, it is on an inconsistent basis.

Even knowing this, we persist in the belief that we can coerce nature to our bidding when and where we please through cloud seeding. The Chinese want to force rain to clear the air before the Olympics. The government of the Philippines, currently in an extended dry spell, are attempting cloud seeding to break the drought. At the request of farmers in Queensland and New South Wales, Australia, cloud seeding is again being pursued. I wish them luck, but whatever success they may have will likely be down to random chance.

While cloud seeding is not especially effective, at least it is relatively harmless, wasting only time and resources. More risky are larger-scale, geo-engineering projects offered up as solutions to anthropogenic warming or as ways to sequester carbon dioxide.

Dumping iron in the ocean to promote plankton growth is bound to have some sort of unexpected outcome. For example, in certain water conditions a plankton bloom can lead to a chain reaction resulting in further oxygen depletion of the water. This places further stress on the already overstressed ocean biosphere, creating a 'dead zone' in the ocean such as those observed off the Oregon coast the last several years. The consequences are potentially large, in theory impacting the food supply.

Proposals to create a 'sunshade' for the planet are potentially even worse. The idea that we can mimic a volcanic eruption and actually control the consequences is madness. Maybe, as an absolute last resort we could think about it, as Climate Progress noted. New Scientist reports that such a screen, incorrectly applied, 'could result in sudden warming – which would be worse than the long-term warming that had been avoided because of its swiftness'. They also report a later study which claimed that 'even if correctly deployed – a sulphur sunshade could have deleterious effects on the environment by reducing rainfall'.

None of this is meant to say that we humans cannot alter our environment. We just cannot control the outcomes or minimize the blowback, especially on regional and planetary scales. And it is the height of hubris to think we can. I would like to believe that we could learn something from the experiment we already have running – the 35% (and rising!) increase of CO2 in the last 100 years. Just look at how well that's turning out!

Here's an idea. Instead of trying to bend Nature to our will, let's cooperate with her. Instead, let's fix our behaviour -- something we can more reliably control-- and reduce our emissions of CO2 to slow the forcing and minimize the damage. It's only human.

01 August 2007

Our old friend Ozone

Ozone (O3) is a trace component in our atmosphere. It is a largely transient substance, with molecules being both created and destroyed mainly by the light of the Sun. Its presence is beneficial in the stratosphere, where it acts to absorb short-wavelength EM radiation. Nearer the surface, the photolysis of the gases (NOX) --in among other things, automobile exhaust -- allows for the production of tropospheric ozone, which typically results in range of health issues, particularly for those with respiratory problems. It is also a greenhouse gas, to boot.

Given this, we generally try to prevent the depletion of stratospheric ozone, while trying to suppress the creation of tropospheric ozone. As a result of climate change, those things may become more difficult.

...projections of increasing ozone near the Earth's surface could lead to significant reductions in regional plant production and crop yields. Surface ozone also damages plants, affecting their ability to soak up carbon dioxide from the atmosphere and accelerating global warming.

This is a pretty good example of a secondary effect and of a positive feedback. Something unintended come back to bite, and make things worse at the same time. However, with the following item, the relation to and the impact from climate change isn't as clear at this time.

Large quantities of ozone-depleting chemicals have been discovered in the Antarctic atmosphere by researchers from the University of Leeds...[finding] found high concentrations of halogens - bromine and iodine oxides -- which persist throughout the period when there is sunlight in Antarctica (August through May).


"Halogens in the lowest part of the atmosphere have important impacts on ozone depletion, the ability of the atmosphere to remove potentially harmful compounds, and aerosol formation. All these atmospheric phenomena are linked to climate change. We still have to work out what the ramifications of this discovery are. These exciting results also show how important it is to keep exploring the atmosphere - there seems to be plenty more to find out."

It is not clear to me that any real impact has been measured, only that it is a possible impact. Still, it is good to know beforehand, rather than finding out too late.