Climate Concern UK - answering scepticism

Reposted from: http://www.climate-concern.com/answering%20scepticism.htm

Global warming: Reasons why it might not actually exist

Reposted from: http://www.telegraph.co.uk/earth/environment/globalwarming/4029837/Global-warming-Reasons-why-it-might-not-actually-exist.html

my comments in green

2008 was the year man-made global warming was disproved, according to the Telegraph's Christopher Booker. Sceptics have long argued that there are other explanations for climate change other than man-made CO2 and here we look at some of the arguments put forward by those who believe that global warming is all a hoax.

Last Updated: 1:51PM GMT 30 Dec 2008

Some icebergs are melting -but not necessarily because of mankind's actions Photo: REUTERS

Temperatures are falling, not rising

As Christopher Booker says in his review of 2008, temperatures have been dropping in a wholly unpredicted way over the past year. Last winter, the northern hemisphere saw its greatest snow cover since 1966, which in the northern US states and Canada was dubbed the "winter from hell". This winter looks set to be even worse.

Is ONE years weather relevant in deciding if global warming or cooling is happening?

The earth was hotter 1,000 years ago

Evidence from all over the world indicates that the earth was hotter 1,000 years ago than it is today. Research shows that temperatures were higher in what is known as the Mediaeval Warming period than they were in the 1990s.

But today we have many more humans on earth...

The earth's surface temperature is not at record levels

According to Nasa's Goddard Institute for Space Studies analysis of surface air temperature measurements, the meteorological December 2007 to November 2008 was the coolest year since 2000. Their data has also shown that the hottest decade of the 20th century was not the 1990s but the 1930s.

But Goddard Institute also say "2008 was the coolest year since 2000, according to the Goddard Institute for Space Studies analysis of surface air temperature measurements. In our analysis, 2008 is the ninth warmest year in the period of instrumental measurements, which extends back to 1880 (left panel of Fig. 1). The ten warmest years all occur within the 12-year period 1997-2008. The two-standard-deviation (95% confidence) uncertainty in comparing recent years is estimated as 0.05°C [ref. 2], so we can only conclude with confidence that 2008 was somewhere within the range from 7th to 10th warmest year in the record."

"Their data has also shown that the hottest decade of the 20th century was not the 1990s but the 1930s." says Christopher Booker. The link given does not substantiate this claim as far as I can tell.

Ice is not disappearing

Arctic website Crysophere Today reported that Arctic ice volume was 500,000 sq km greater than this time last year. Additionally, Antarctic sea-ice this year reached its highest level since satellite records began in 1979. Polar bear numbers are also at record levels.

Himalayan glaciers

A report by the UN Environment Program this year claimed that the cause of melting glaciers in the Himalayas was not global warming but the local warming effect of a vast "atmospheric brown cloud" over that region, made up of soot particles from Asia's dramatically increased burning of fossil fuels and deforestation.

Temperatures are still dropping

Nasa satellite readings on global temperatures from the University of Alabama show that August was the fourth month this year when temperatures fell below their 30-year average, ie since satellite records began. November 2008 in the USA was only the 39th warmest since records began 113 years ago.

David Cameron sets out £1bn 'smart grid' plan for green Britain

David Cameron has said a Conservative Government will cut Britain's greenhouse gas emissions with a £1 billion investment to provide a "smart meter" in every home.

 

Last Updated: 3:14PM GMT 16 Jan 2009

Mr Cameron described the new technology - also expected to form part of incoming US President Barack Obama's massive infrastructure programme - as 'the internet for electricity'. Photo: Getty

 

The Tory leader said that the new smart grid technology was capable of delivering a "genuinely low-carbon world".

The project will form the centrepiece of a Green Paper setting out the Tory vision of a low-carbon economy, which Mr Cameron will unveil in an Internet-based launch event today.

The proposed smart grid would allow energy companies to tell people when they can buy electricity at the cheapest rates, as well as allowing consumers to feed power from solar panels back into the network.
It is hoped that the changes would significantly reduce electricity use, cutting customers' bills and slashing Britain's contribution to the carbon dioxide emissions which are blamed for global warming.

"It is the thing that brings our plans all together, that makes it all possible and will deliver a genuinely low-carbon world," said the Tory leader.
Mr Cameron said that the Tories have already had discussions with National Grid officials about the practicalities of installing the new technology and will be able to approve the investment as soon as they come to office.

Sense and Nonsense in Climate Change - David Warden at Dorset Humanists

On 10th January 2009 at Dorset Humanists (Bournemouth, Dorset UK) David Warden gave his views on the Climate Change debate. My comments in green. David Wardens answers in yellow.

• Man made emissions of CO2 - 30 Billion Tonnes v x Quadrillion Tonnes gases in the atmosphere.
• Total atmosphere NOT Carbon is 99.9% at current CO2 levels of 380ppm. The reason David turned "380ppm" into "99.9% carbon free" was really to highlight the fact that we are so easily swayed by the way data is presented.
• If CO2 levels double the figure will be 99.4%. cf homeopathy. Crabsallover: 'No explanation why CO2 / Methane /NO2 are such potent green house gasses was discussed.' David: "The potency of CO2 is believed to be enhanced by a secondary effect: global warming leads to evaporation which adds the greenhouse effect of water vapour. Sooner or later water vapour gets washed out as rain, so this theory is highly debateable. Methane is a potent greenhouse gas but there’s very little of it in the atmosphere. There’s also a tiny amount of NO2 in the atmosphere."
• "the most surprising fact about global warming is that it is not, at the present time, happening." Nigel Lawson
• compared arguements of Catastrophist (the Cats) with Moderates (the Mods)
• IPCC - remit is to assess understanding of human-induced climate change - but not climate change in general. Crabsallover 'IPCC brief is much wider than David Warden suggested and includes a full overview of Climate Change. Twenty one years ago UNEP and WMO established the Intergovernmental Panel on Climate Change (IPCC) to provide independent scientific advice on the complex and important issue of climate change. The Panel was asked to prepare a report on all aspects relevant to climate change and its impacts and to formulate realistic response strategies. I told David Warden that greater attention should have given in this talk to the findings of the 4 reports in 1990, 1995, 2001 and 2007 - with each IPPC report the probability of man made climate change through increasing CO2, has increased." David"I think we would have got totally bogged down if I had attempted to appraise 4 massive IPCC reports. I was making the more general point that the IPCC has been criticised by the sceptical scientists, particularly its summaries for policymakers which iron out a lot of the scientific uncertainties, rather like Blair’s ‘dodgy dossier’ on Iraqi WMD." I say "I would expect the 22 page Summaries for Policymakers to simplify some of the science presented in the 52 page Synthesis report, Which scientific uncertainties were 'ironed out'? Did this mean that Policymakers were somehow misled?
  
• Joseph Fourier discovered greenhouse gases in 1824
• Average greenhouse emmsission per person: 11T - UK, 2T India, 20T USA
• 2% of global CO2 emmissions are from the UK
• 99.9% of atmosphere is C free, 0.8 degree C rise in global temperatures since 1850
• NIPCC - Fred Singer (Nature, not Humans, rules the Climate). Crabsallover 'some scientists have dismissed Singer's most recent report on global warming as "fabricated nonsense".'
• Kyoto cost $150Bn pa - would money be better spent on reducing poverty worldwide?
• in Cretaceous the sea level was 650' higher than today (twice height of St Pauls Cathedral!)
• Sawtooth graph: annual changes in temperature levels due to plant growth/decay - mostly fluctuating - whilst CO2 levels rise
  
• Hockey stick graph (IPCC)
• IPCC - a doubling of CO2 will give a temperature rise of 1.1-6.4 degrees - IPCC (6 Scenarios, Table 3.1, http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf )
• David said in this posts 5th comment "A large part of the sceptical case is discontent with the whole IPCC process - described by Nigel Lawson as science by committee - leading to a politically manufactured consensus from which few are brave enough to dissent.
  
• David Warden said 'you can prove anything with graphs'
  
• Gaia Hypothesis - James Lovelocke
  
• CO2 levels - 350ppm levels (= 350*100%/1,000,000) = 0.35%
• Russian Scientist - a big freeze by 2050?
• Hole in greenhouse blancket discovered in Pacific Ocean in 2001
• Sea Level rises in 21st Century: IPCC estimate 2', Al Gore 20', James Hansen 80'
• Sea Level rises if ALL of these land mass melted: Greenland 23', Antarctica 200' (West Antarctica 16')
• Geological timescale eg; Eon - Phanerozic ; Era - Mesozoic; Period - Quarternary; Epoch - Eocene
• Rachel Carson book Silent Spring book led to a ban on DDT which lead to many dying from malaria
• flooding of Maldives (no mention of Bangladesh). David answers "I omitted this for reasons of time: A 2 foot sea level rise is likely to be a problem but not a catastrophe. For low-lying countries like Bangladesh, it’s likely to be a problem (about 50% of the land would be flooded if the sea level were to rise by 3 feet) but as Bangladesh gets richer, it’ll find ways to manage or mitigate the problem such as building sea defences. The Bangladesh economy has been growing at about 5-6% over recent years and poverty has fallen by 20% since the early 1990s. But even without global warming, Bangladesh will always be a geographically vulnerable place for human beings to live. Just as Florida is a geographically vulnerable place for human beings to live."
• post Kyoto costs will be $8 Trillion (Fred Pierce)
  
• climate change is a secular religion, Spanish Inquisition against climate change deniers!

David Warden Summary

1. 'their is a fairly weak correlation between CO2 levels and temperature'
2. 'global warming is not a serious threat to man'
3. "At most, we may see a total rise of about 2 or 2½°C during the 21st century over and above the temperature in 1850 (and this includes the 0.8C rise between 1850-2000) ie a 1.2 or 1.7°C rise during 21st over 1850-2000 period".
4. "this 2 or 2½°C temperature rise will be mostly beneficial."
5. 'global cooling may happen by 2050'
6. 'governments are agreeing to target of a 2 degree rise because that is what will happen naturally whether man intervenes or not to stop Climate Change'

My Interpretation of David Warden Summary

1. 'their is a fairly weak correlation between CO2 levels and temperature'. Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations. (IPCC Synthesis summary, pg 5)
2. 'global warming is not a serious threat to man'. if DW scenario (increase of 1.1-1.7C by end 21st century), IPCC say that up to 30% species at risk of extinction, most corals bleached, increased damage from floods and storms. (IPCC Synthesis Report).
3. "At most, we may see a total rise of about 2 or 2½°C during the 21st century over and above the temperature in 1850 (and this includes the 0.8C rise between 1850-2000) ie a 1.2 or 1.7°C rise during 21st over 1850-2000 period". See following graphs (click for larger graph) incl. David Warden (DW) 1.2-1.7C scenario v IPCC 6 scenarios (IPCC Synthesis Report).
   

Comments by Audience

• Sue Chapman: Iain Stewart programme - Earth: The Climate Wars; Nigel Lawson excludes CO2 levels - his book is a work of fiction, 11thhourproject,
  
• Harry: 30K scientists signed up to Kyoto Protocol
• I said "Stern Report - will cost 1-2% GDP to correct problem if act now vs 8% GDP if act in 2030"
  
• I said "vast majority of scientists agree that climate change is happening and it is man made." David answers "I don’t think this argument can be settled on a number count. We need to listen to climate scientists. All of them, including the sceptics, agree that climate change is happening and that part of it is man made."I say' Agreed, most importantly we must listen and act on what climate scientists are saying. The IPCC say Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic (man made) Green House Gas concentrations. (IPCC Synthesis summary, pg 5)'
• Paul Entwhistle: Royal Society (1400 members) report on Climate Change - page / pdf; ask MP to vote for Early Day Motion EDM 21; on ; albedo effect; solar power; desalination;
  
• a lady 'no kind of concensus amongst scientists'
• albedo effect
  
• Roger West: 'High voltage direct current', Solar Power / Desalination.
  

Hockey stick graph controversy

Reposted from: http://en.wikipedia.org/wiki/Hockey_stick_graph

The hockey stick controversy is a dispute over the reconstructed estimates of Northern Hemisphere mean temperature changes over the past millennium especially the particular reconstruction of Mann, Bradley and Hughes, aka MBH98 reconstruction.

The lower graph was included in the 1990 Ist IPCC report. The Hocky Stick graph was included in the IPCC 2001 Third Assessement Report (pg 3) but not included in the IPCC 4th 2007 report.

More ....

In September 2008, Mann et al published an updated reconstruction of Earth surface temperature for the past two millennia.^[61] Similarly to the original 1998 study, this work found that recent increases in northern hemisphere surface temperature are anomalous relative to at least the past 1300 years.

The debate continues...

Mark Lynas - Six Degrees

Reposted from: http://www.green.tv/6_degrees

10 minute film by Mark Lynas - Six Degrees - presents the six IPCC scenarios in graphic detail!

Also here Mark Lynas explains his book Six Degrees (1min 30secs):

IPCC - Guardian articles

Reposted from: http://www.guardian.co.uk/environment/ipcc

Cost of tackling global climate change has doubled, warns Stern

Reposted from: http://www.guardian.co.uk/environment/2008/jun/26/climatechange.scienceofclimatechange

· Author of landmark report says 2% of GDP is needed
· Inaction would mean far greater economic damage

• Juliette Jowit and Patrick Wintour
• The Guardian, Thursday 26 June 2008

Lord Stern believes £28bn may be need to tackle climate change. Photograph: PA

The author of an influential British government report arguing the world needed to spend just 1% of its wealth tackling climate change has warned that the cost of averting disaster has now doubled.

Lord Stern of Brentford made headlines in 2006 with a report that said countries needed to spend 1% of their GDP to stop greenhouse gases rising to dangerous levels. Failure to do this would lead to damage costing much more, the report warned - at least 5% and perhaps more than 20% of global GDP.

But speaking yesterday in London,

Stern said evidence that climate change was happening faster than had been previously thought meant that emissions needed to be reduced even more sharply.

This meant the concentration of greenhouse gases in the atmosphere would have to be kept below 500 parts per million, said Stern. In 2006, he set a figure of 450-550ppm. "I now think the appropriate thing would be in the middle of that range," he said. "To get below 500ppm ... would cost around 2% of GDP."

In a recent report for the London School of Economics,

Stern acknowledged that even 1% of GDP was "not a trivial amount". For the UK it is equivalent to £14bn a year. But he argue that it was a fraction of annual economic growth, and much less than the 8-14% that was spent, for example, on health by industrialised countries.

His reassessment of the cost of battling climate change comes at a sensitive time, the day before Gordon Brown makes a major speech setting out a £100bn strategy for ensuring that 15% of all energy used in the UK will come from renewable sources by 2020. The government has come under pressure from the Tories, whose statements on the environment include effectively banning new coal power stations and opposing a third runway at Heathrow.

Speaking yesterday at the launch of the Carbon Rating Agency, the world's first ratings agency for carbon offsetting projects, Stern warned that the 2% estimate required governments to act quickly. "All this depends on good policy and well functioning [carbon] markets. There are many ways to mess this up, many ways of acting to make it more costly," he said.

The Stern review in October 2006 called for global emissions to be cut by a quarter by 2050 and to be stopped from rising above the equivalent of 550ppm of CO2, a measure that combines the effect of all the greenhouse gases. The current level is 430ppm, and is rising by 2ppm a year.

Yesterday, Stern, a former World Bank chief economist and head of the UK government economic service, said

he now believed the limit should be 500ppm. This would reduce the risk from a 50% chance to a 3% chance that the global average temperature would rise by 5C above pre-industrial levels,

he said, pointing out that the last time this happened, 35-55m years ago, alligators lived near the north pole. "These kind of temperature changes transform the word," he said.

His new comments follow a speech in April in which he said that the latest research showed climate change was more of a threat, and called for global emissions to halve by 2050, including cuts of 80% in the UK and 90% in the US.

The Department for Environment said the case for cutting global emissions was still strong: "We cannot afford inaction on climate change. Even at the upper range of the estimates, the cost of avoiding dangerous climate change is much lower than even the most conservative estimates of inaction."

The Confederation of British Industry said Stern's latest figures should add to pressure for government and businesses to act quickly to avoid the costs rising further.

"This only reaffirms the need to tackle climate change as an immediate priority and highlights both the benefits of early action and the cost of inaction," said Neil Bentley, CBI Director of Business Environment.

Stern Review on the Economics of Climate Change

The Stern Report (Nicholas Stern, Wikipedia & Stern Review, Wikipedia)

Its main conclusions are that one percent of global gross domestic product (GDP) per annum is required to be invested in order to avoid the worst effects of climate change, and that failure to do so could risk global GDP being up to twenty percent lower than it otherwise might be. Stern’s report suggests that climate change threatens to be the greatest and widest-ranging market failure ever seen, and it provides prescriptions including environmental taxes to minimize the economic and social disruptions. He states, "our actions over the coming few decades could create risks of major disruption to economic and social activity, later in this century and in the next, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century."

In June 2008 Stern increased the estimate to 2% of GDP to account for faster than expected climate change.

Download Stern Report from HM Treasury.

In this post I have reviewed the key points I've taken from the Executive Summary (4 page short pdf).

A longer 22 page Executive Summary pdf has diagrams.

• There is still time to avoid the worst impacts of climate change, if we take strong action now.
• the benefits of strong and early action far outweigh the economic costs of not acting.
• if we don’t act, the overall costs and risks of climate change will be equivalent to losing at least 5% of global GDP each year, now and forever. If a wider range of risks and impacts is taken into account, the estimates of damage could rise to 20% of GDP or more. In contrast, the costs of action – reducing greenhouse gas emissions to avoid the worst impacts of climate change – can be limited to around 1% of global GDP each year.
• The investment that takes place in the next 10-20 years will have a profound effect on the climate in the second half of this century and in the next. Our actions now and over the coming decades could create risks of major disruption to economic and social activity, on a scale similar to those associated with the great wars and the economic depression of the first half of the 20th century. And it will be difficult or impossible to reverse these changes. (I understand by this that if we dont take action then these will be the consequences)
  
• So prompt and strong action is clearly warranted. Because climate change is a global problem, the response to it must be international.
• Climate change could have very serious impacts on growth and development.
• If no action is taken to reduce emissions, the concentration of greenhouse gases in the atmosphere could reach double its pre-industrial level as early as 2035, virtually committing us to a global average temperature rise of over 2°C.
• In the longer term, there would be more than a 50% chance that the temperature rise would exceed 5°C. This rise would be very dangerous indeed; it is equivalent to the change in average temperatures from the last ice age to today. Such a radical change in the physical geography of the world must lead to major changes in the human geography – where people live and how they live their lives.
• All countries will be affected. The most vulnerable – the poorest countries and populations – will suffer earliest and most, even though they have contributed least to the causes of climate change. The costs of extreme weather, including floods, droughts and storms, are already rising, including for rich countries.
• Adaptation to climate change – that is, taking steps to build resilience and minimise costs – is essential. It is no longer possible to prevent the climate change that will take place over the next two to three decades, but it is still possible to protect our societies and economies from its impacts to some extent – for example, by providing better information, improved planning and more climate-resilient crops and infrastructure. Adaptation will cost tens of billions of dollars a year in developing countries alone, and will put still further pressure on already scarce resources. Adaptation efforts, particularly in developing countries, should be accelerated.
• The costs of stabilising the climate are significant but manageable; delay would be dangerous and much more costly.
• The risks of the worst impacts of climate change can be substantially reduced if greenhouse gas levels in the atmosphere can be stabilised between 450 and 550ppm CO2 equivalent (CO2e). The current level is 430ppm CO2e today, and it is rising at more than 2ppm each year. Stabilisation in this range would require emissions to be at least 25% below current levels by 2050, and perhaps much more.
• Ultimately, stabilisation – at whatever level – requires that annual emissions be brought down to more than 80% below current levels.
• This is a major challenge, but sustained long-term action can achieve it at costs that are low in comparison to the risks of inaction. Central estimates of the annual costs of achieving stabilisation between 500 and 550ppm CO2e are around 1% of global GDP, if we start to take strong action now.
• It would already be very difficult and costly to aim to stabilise at 450ppm CO2e. If we delay, the opportunity to stabilise at 500-550ppm CO2e may slip away.
• Action on climate change is required across all countries, and it need not cap the aspirations for growth of rich or poor countries.
• The costs of taking action are not evenly distributed across sectors or around the world. Even if the rich world takes on responsibility for absolute cuts in emissions of 60-80% by 2050, developing countries must take significant action too. But developing countries should not be required to bear the full costs of this action alone, and they will not have to. Carbon markets in rich countries are already beginning to deliver flows of finance to support low-carbon development, including through the Clean Development Mechanism.
• The world does not need to choose between averting climate change and promoting growth and development. Changes in energy technologies and in the structure of economies have created opportunities to decouple growth from greenhouse gas emissions. Indeed, ignoring climate change will eventually damage economic growth.
• Tackling climate change is the pro-growth strategy for the longer term, and it can be done in a way that does not cap the aspirations for growth of rich or poor countries.
• A range of options exists to cut emissions; strong, deliberate policy action is required to motivate their take-up.
• Emissions can be cut through increased energy efficiency, changes in demand, and through adoption of clean power, heat and transport technologies. The power sector around the world would need to be at least 60% decarbonised by 2050 for atmospheric concentrations to stabilise at or below 550ppm CO2e, and deep emissions cuts will also be required in the transport sector.
• Even with very strong expansion of the use of renewable energy and other low carbon energy sources, fossil fuels could still make up over half of global energy supply in 2050. Coal will continue to be important in the energy mix around the world, including in fast-growing economies. Extensive carbon capture and storage will be necessary to allow the continued use of fossil fuels without damage to the atmosphere.
• Key elements of future international frameworks should include:
• Emissions trading: Expanding and linking the growing number of emissions trading schemes around the world is a powerful way to promote cost-effective reductions in emissions and to bring forward action in developing countries: strong targets in rich countries could drive flows amounting to tens of billions of dollars each year to support the transition to low-carbon development paths.
• Technology cooperation: Informal co-ordination as well as formal agreements can boost the effectiveness of investments in innovation around the world.
• Action to reduce deforestation: The loss of natural forests around the world contributes more to global emissions each year than the transport sector. Curbing deforestation is a highly cost-effective way to reduce emissions; largescale international pilot programmes to explore the best ways to do this could get underway very quickly.
• Adaptation: The poorest countries are most vulnerable to climate change. It is essential that climate change be fully integrated into development policy, and that rich countries honour their pledges to increase support through overseas development assistance.

Sir John Houghtons' critque of Nigel Lawsons' book - Summarised with diagrams from IPCC reports

Sir John Houghton (in Nature and a longer critique) says that Nigel Lawsons' book 'An Appeal to Reason' is largely one of misleading messages. In this post I've discussed his shorter critique in Nature magazine.

The first of the misleading messages Houghton says is Lawsons' "questioning of the reality of human-caused global warming itself... Lawson takes the record of global average temperature in the first seven years of this century as evidence that the scientists must have it wrong. By themselves, these years show no significant increase in temperature, but they are warmer on average by almost 0.1 °C than the previous seven years.

Even a casual inspection of the global record from 1970 shows two things: first a clear trend of about a 0.5 °C increase over the past 30 years, and second a substantial year-to-year variability of the kind that is well known to climatologists and has been attributed to phases of the El Niño/La Niña phenomenon, a regular feature of the Pacific climate (see Figure SPM.1 (left) from IPCC 2007 Summary for Policymakers, pg 3)

Lawson challenges the carefully worded conclusion of the UN's Intergovernmental Panel on Climate Change that "most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations." He does this, not with any analysis of his own, but by listing some of the sources of uncertainty that are in any case are thoroughly addressed by the IPCC.



Lawson argues that even if global average temperature increased by about 3 °C, such warming would be trivial, and even largely beneficial. But given that the difference in temperature between the middle of an ice age and the warm periods in between ice ages is only 5 or 6 °C, (I could not find evidence for these ice age figures, when I looked here) an increase of 3 °C , occurring over much shorter time periods — on the scale of centuries rather than millennia — is far from inconsequential.

Although they receive extensive coverage in the IPCC reports, Lawson completely ignores some of the most serious impacts of global warming: namely the floods and droughts that are expected to become more frequent and more severe with even small rises in temperature. (see diagram - Examples of impacts associated with global average temperature change from Summary for Policymakers, pg 10)



Considering the potential for more climate extremes and sea level rise in the future, there are likely to be hundreds of millions of refugees from the world's most affected nations. Where could those people go in our increasingly crowded world? Lawson denies that there is any problem.

He repeats a number of times his summary of the damage as the difference between people in the developing world being 8.5 times better off than they are now and the 9.5 times improvement that they would see in the absence of global warming. Sleight of hand with gross numbers of possible economic growth must not be allowed to hide the magnitude of the very real problems.

The 2007 IPCC report makes it clear that the anticipated impacts of global warming will lead to tens or hundreds of millions of people suffering loss of resources, livelihoods and land. For example impact of climate change in Africa (see diagram from Working Group 2 Summary for Policymakers Report, pg 13)



But even if such impacts were likely, we cannot afford to address them, says Lawson. To stabilize atmospheric concentrations of greenhouse gases during this century, emissions would have to be substantially reduced from today's levels by mid-century. And because carbon dioxide emitted into the atmosphere remains there on average for around 100 years, there is an urgent need to begin reductions now. Lawson writes this off as being difficult, inconvenient and very costly. But both the International Energy Agency and Shell have recently presented scenarios of changes in energy generation and use by 2050 that show it would be feasible to move substantially towards achieving the emissions reductions required. How great, then, is the cost?

The Stern Review on the Economics of Climate Change indicates that if we act quickly, this could be as little as a few per cent of GDP by 2050. Executive summary of Stern Report - my key points are here.

Crucially, delayed action will increase the price tag, with the cost of doing nothing and paying to adapt to change much greater than that of early mitigation.

Lawson begs to differ, arguing that the financial burden of reducing emissions sharply would simply be unjustified in the face of scientific uncertainty.