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Most governments in the developed world were elected on platforms that promised aggressive policies on greenhouse gas emissions. The reality has not matched the commitments made. The reasons for this are multitudinous and no one should ever underestimate the difficulties of weaning advanced societies off the use of cheap and convenient access to fossil fuels. But in addition to the standard reasons for slow progress we can see a large number of obstacles that spring from human psychology. In particular, some of the resistance to aggressive action on climate seems to spring from mental attitudes that may have helped us survive as a species in the past. Perhaps politicians intuitively recognise the existence of these barriers. So they continue to say that climate change is the most important problem facing humanity at the same time as adding new runways to the local airport or sanctioning the development of new coal-fired power stations.

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Pinus edulis (piñon shortened pine) before and after drought. Image source: Southwest Colorado Wildflowers.

Pinus edulis (piñon shortened pine) before and after drought. Image source: Southwest Colorado Wildflowers.

Perhaps this isn’t surprising, but a new piece of research shows that the ability of trees to survive drought is reduced when temperatures are higher.[1] A species of pine that grows in dry conditions was exposed to temperatures 4.3 degrees higher than a control group. Both sets of trees were kept without water. The trees in the hotter atmosphere typically died in 18 weeks compared to the 25 weeks of the control.

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Why is humanity finding it difficult to take action on climate change?
Most governments in the developed world were elected on platforms that included promises to pursue aggressive policies on greenhouse gas emissions. Broadly speaking, the reality has not matched the promises made. The reasons for this are multitudinous and no one should ever underestimate the difficulties of weaning advanced societies off the use of cheap and convenient access to fossil fuels. But in addition to the standard reasons for slow progress we can see a large number of obstacles that spring from human psychology. In particular, some of the resistance to aggressive action on climate seems to spring from mental attitudes that may have helped us survive as a species in the past. Politicians may intuitively recognise the existence of these barriers. So they continue to say that climate change is the most important problem facing humanity at the same time as adding new runways to the local airport or sanctioning the development of new coal-fired power stations.

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Nigel Lawson and others are suggesting that temperatures have ‘stabilised’ since the late nineties. 1998 saw the highest global average temperature and only 2005 has closely matched it. Since no year since 1998 has exceeded the record, some commentators are saying the global warming has stopped. The implication, sometimes stated, sometimes not, is that the increasing rate of growth of CO2 concentration is having no effect on temperature.

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The Heartland Institute, a US free-market think tank, held a conference on climate change in New York in early March. It was a forum for some of the climate change sceptics to discuss their research. The conference got very little coverage in the media and was ignored by the science pages of the newspapers.

This seems a mistake. A large section of the population of the US and the UK, and smaller numbers elsewhere, believe that the apparent scientific consensus on global warming is a result of selective coverage by TV and press. The failure to cover presentations by some of the leading sceptics is support for the accusation that global media, and mainstream climate scientists, are refusing to engage with the dissenting views of reputable scientists who do not share the standard view.

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Switchgrass biofuel crop
Switchgrass biofuel crop

Will next-generation biofuels have a less destructive effect on agriculture? A study just published by US government scientists suggests that so-called ‘cellulosic’ ethanol has much better energy balance than today’s biofuels.[1] By energy balance, we mean the energy used to make the fuel compared to its energy value when burnt in a car’s engine. News summaries of the paper’s contents focused on one estimate that suggested that to make cellulosic biofuels might only need 6% of the energy value contained in the fuel. Depending on which crop is used, where it is grown, and how it is refined, most of today’s biofuels have only a weakly positive energy balance. So the paper gives hope that we might expect considerable progress towards carbon-neutral transport fuels when we can start refining all vegetable matter, not just foodstuffs, into fuels.

Cellulosic biofuels may well become important sources of motor fuels. There is certainly huge amounts of money flowing into the field. Unfortunately none of the news articles covering the US research pointed out the technology for turning cellulose into fuel is still a long way from commercial viability. Yes, we can turn grass into ethanol, but at prices which will double the price of petrol. And the greenhouse gas savings will almost certainly not be as attractive as the paper suggests, not least because the authors did not include the serious impact of nitrous oxide emissions from fertilised fields.

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Carbon dioxide levels in the atmosphere rise by about 2-3 parts per million every year and the rate is slowly increasing. As well as this upward trend, there is an annual cycle: carbon dioxide levels fall in the northern hemisphere summer and rise strongly in the winter. The reason is that most of the vegetated land area is in the northern hemisphere and during the northern summer plants and trees absorb CO2.One effect of increasing spring and autumn temperatures has been to increase the length of what is loosely called ‘the growing season’. Plant growth can start earlier in spring and can continue until later. It might be thought that this would help vegetation take up more CO2, acting as a counterweight to increased fossil fuel use.

Research published in Nature in early January very strongly suggests that this is not happening. Warmer autumns are associated with a bringing forward of the date at which plants start losing CO2, not the reverse. Higher spring and autumn temperatures are tending to decrease the length of the period each year in which northern hemisphere plants are taking up carbon. If this research is confirmed, this is yet another potential positive feedback because higher temperatures might diminish the ability of biomass to take up carbon.

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The IPCC released a 23-page report summarising the work of the fourth phase. Newspaper headlines suggested the document was more apocalyptic than the third summary of 2001. The reality is more complex.

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CO2 output is accelerating, the ocean and land sinks are getting less effective at absorbing it. So the rate of growth of carbon dioxide in the atmosphere is increasing.

(Canadell, Le Quéré, and others, ‘Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks’, Proceedings of the National Academy of Sciences, 25 October 2007; URL: http://tinyurl.com/yqew8o [accessed 27 October 2007].)

The pre-industrial CO2 concentration in the atmosphere was about 280 parts per million. It was 381ppm in 2006. The growth rate between 2000 and 2006 was 1.93ppm, a significant increase on growth rates in earlier periods. Many policy-makers see it as vital to keep below concentrations of about 400ppm of CO2. The increase in the rate of rise of CO2 makes the achievement of this target more difficult.

Increases in the amount of CO2 in the atmosphere reflect the volume of global emissions and the effectiveness of the oceans and land mass in absorbing greenhouse gases. This paper contains evidence both that emissions growth is speeding up and that the greenhouse gas sinks are capturing less CO2.

The growth rate in emissions between 2000 and 2006 was 3.3% a year compared to 1.3% in the 1990s (please see the article on Chinese exports in this issue of Carbon Commentary for corroboration of this finding). This increase reflects fast economic growth, particularly in China and India and a worrying increase in the amount of CO2 produced per unit of global output. It cannot be stressed enough that this second cause of emissions growth is unexpected. We thought we were going to see energy use fall in relation to economic output.

By contrast, models have predicted a decline in the effectiveness of ocean CO2 ‘sinks’. This paper shows that we can have a strong suspicion (but not near certainty) that this process has started. The authors point to increasing wind speeds in the Southern Ocean as a primary cause. This turbulence ‘ventilates’ the carbon dioxide contained in the surface of the sea. Droughts in mid-latitude regions have contributed to the decreased efficiency of land absorption.

The paper concludes that – with large margins of error – economic growth generated 65% of the increase in atmospheric CO2; the decrease in the efficiency of the sinks generated another 18% and caused a rise in the carbon output required to generate a dollar of world GDP.

The authors summarise by saying that their results ‘characterize a carbon cycle that is generating stronger-than-expected and sooner-than-expected climate forcing’.

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Bjørn Lomborg, a professor at Copenhagen Business School, is the most formidable critic of those who think that cutting climate-changing gases is the most important problem the world faces. He made his name with ‘The Skeptical Environmentalist’ and his new book continues his drive to get the world to see global warming as just one of the world’s important problems.

Lomborg believes climate change is happening, and that mankind’s activities are responsible. But he tells that we shouldn’t do much about global warming because the costs are very high and the benefits are limited and far-off. Like most books written by partisans in this impassioned debate, much of what he says can be questioned.

Nevertheless, this is an extremely valuable polemic: it stresses repeatedly that taking action to stop climate change may have very high short-term costs. If by clumsy attempts to hold down emissions we stunt the prospects for global economic growth, we may do more harm to the world’s poor than would be inflicted by climate change. It needs to be said time and time again that disease and malnutrition are killing far more people today than climate change. We are making progress diminishing the impact of these scourges. Despite what you sometimes read in the newspapers, world food supply and life expectancy are improving. Panic-stricken action on climate change must not be allowed to halt this progress. We need a rational assessment of whether it is best to spend money on slowing climate change or to whether we would achieve better effects from focusing resources elsewhere.

Bjørn Lomborg is an able debater with a passionate interest in his subject. But he overstates his case, focuses on only parts of the issue and avoids any discussion of a possible future acceleration of global warming. Even with these weaknesses Cool It needs to be part of the continuing debate on how to respond to the climate threat without crippling the poorest economies of the world.

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