David Hone

Last week PWC released the 2012 version of its “Low carbon economy index”, the fourth edition of a publication that started just prior to the Copenhagen COP. The main message delivered by the publication is a grim one, although hardly surprising, that the much discussed 2°C target is now effectively out of reach.

 We estimate that the world economy now needs to reduce its carbon intensity by 5.1% every year to 2050 to have a fair chance of limiting warming to 2°C above pre-industrial levels. Even to have a reasonable prospect of getting to a 4°C scenario would imply nearly quadrupling the current rate of decarbonisation. The decarbonisation rate required for a 2°C world has not been achieved in a single year since World War 2. The closest the world came to that rate of decarbonisation was during the severe recessions of the late 1970s/early 1980s (4.9% in 1981) and the late 1990s (4.2% in 1999). The expected reduction in emissions resulting from the current economic slowdown has not materialised, partly because of sustained growth in emerging markets.

Even more bad news follows, with an analysis of the various national pledges made following the Copenhagen COP. Not only does the publication make it clear that the cumulative impact of the stated contributions is insufficient for a 2°C pathway, but that many nations appear to be falling short of actually meeting them.

Even more worryingly, with eight years to go, it is questionable whether several of these pledges can be met.

The resurgence of gas in the global energy mix features in the report as an important driver of change, albeit with the concern about long term lock-in. Nevertheless, growth in natural gas production is leading to a real reduction in emissions in some parts of the world, but particularly the United States.

No matter which country or region you look at, progress made is pretty dispiriting. In a table of some 20 key countries, the worst performer in 2011 was Australia, although over the last decade it hasn’t done too badly in terms of its change in carbon intensity. I suspect that is more due to the fact that it didn’t plunge into recession like almost everybody else, so carbon intensity continued to fall as growth remained high. Therein lies a problem with using carbon intensity as the metric – appearances can sometimes be deceiving.

With 2°C pretty much condemned to the history books, the report goes on to look at the increasing risk of a much higher temperature rise over this century. Even the possibility of an excursion to 6°C is mooted. This outlook isn’t too far off the Shell Scramble (2008) scenario which resulted in CO₂e levels approaching 1000 ppm by the end of the century and a consequent temperature rise of over 4°C and rising. By contrast, Blueprints saw temperatures beginning to plateau at between 2°C and 3°C.

None of this is good news, particularly given the amount of change that can take place in the global ecosystem as a result of small changes in temperature. Take sea level, for example. Although it could take well over a millennium to reach a new equilibrium level, the end result is incredibly temperature sensitive. We shouldn’t be surprised by this given that sea level was over 100 metres lower than today during the previous ice age, when temperatures were lower by about the amount we are worried they may rise in the future. As indicated below, a shift from 2°C to 2.5°C adds about 10 metres of eventual sea level rise (although not anytime soon).

All this raises the question as to what we should or could do, given that 2°C is not feasible. The “numbers guys” at PWC don’t go there and arguing for a higher target is a political non-starter, but at some point the discussion is going to have to happen.

 Based on the work of Allen, Meinshausen et al, which equates a given stock of atmospheric CO2 with long term temperature rise, it is possible to derive a chart which shows, for a given annual reduction until emissions are zero, the impact in terms of expected (midpoint) temperature rise.

For example, starting today, 2°C requires about a 2.5% year on year reduction in emissions – and this is now deemed infeasible by PWC. But if we delay until 2025, the required reduction is over 4% p.a.

Knowing that the world isn’t going to do much until 2020 when a new global agreement is scheduled to kick in, a 2.5°C goal requires about a 1.6% p.a. reduction, assuming action starts immediately. This would mean no new emissions from 2020, plus some 100 very big CCS projects (1 GW power station) starting up each year through the 2020s on existing facilities – and so on. This isn’t very different to the rate at which new coal fired power plants are appearing today, so it is probably feasible from an implementation perspective. Of course keeping all other emissions in check will be a further challenge, but that task could potentially be achieved by aggressive fuel switching and renewable energy deployment, supported by efficiency improvements.

The PWC report is a timely reminder of the situation that we are now in and the ambition that the proposed new global agreement is going to have to aspire to.

•  Allen, M. R. et al (2009) Warming caused by cumulative carbon emissions towards the trillionth tonne, Nature, 458:1163-1166, which argues that a one trillion tonne release of carbon gives a most likely warming of 2°C, with a likely (one-sigma) uncertainty range of 1.6-2.6°C.
• Meinshausen, M. et al (2009) Greenhouse gas emission targets for limiting global warming to 2°C, Nature, 458:1158-1162, which argues that a total release of 0.9 (0.71) trillion tonnes of carbon gives a 50% (25%) risk of temperatures exceeding 2°C.
• Allen, M. R. et al (2009) The Exit Strategy, Nature Reports Climate Change, 3:56-58, which provides a commentary on the implications of the above papers for non-specialists.

If you dig down a few layers through the US State Department website, you will come across a Press Release from February 2010 where the USA pledged to reduce its greenhouse gas emissions.

Press Statement

Todd Stern,  Special Envoy for Climate Change Washington, DC

February 4, 2010

Special Envoy Stern: We are pleased to be among 55 countries – including all of the world’s major economies — that have submitted pledges to limit or reduce their greenhouse gas emissions under the Copenhagen Accord. These countries represent nearly 80% of global emissions. In supporting the Accord, we are taking an important step in the global effort to combat climate change.

In addition to the countries that have submitted targets or actions, a number of others have conveyed their support for the Accord. We urge all countries to join this broad coalition by promptly conveying their support for the Accord to the UNFCCC Secretariat.

The Copenhagen Accord includes important advances on funding, technology, forestry, adaptation and transparency. The United States is committed to working with our partners around the world to make the Accord operational and to continue the effort to build a strong, science-based, global regime to combat the profound threat of climate change.

I have commented on the commitment in previous postings, but just to be reminded of what was said, here is a copy of the letter sent by the US to the UNFCCC. 

Last week the US EIA released the latest greenhouse gas emission figures and they show that the country is well on track to meet this pledge, even though there is no formal program in place to ensure delivery. 

Following the sharp recession led drop, two continuing drivers for the change are the drop in coal emissions as older coal fired power plants close and the fall in automotive emissions due to tougher vehicle efficiency standards and the continuing higher oil price. As expected, natural gas emissions have risen as this fuel replaces coal in power generation, but with less than half the carbon footprint of the coal.

This trend could well continue over the coming years as further coal capacity is closed in response to the combination of EPA air quality regulation, expected greenhouse gas regulation and the growing supply of natural gas. In addition, CAFE standards should ensure further improvements in vehicle efficiency.

My original analysis of this trend produced the following chart. Two years on and we still seem to be at least in the same ballpark.

After two busy weeks, the Durban COP was extended by a full day and then went well into a second, with long nights of negotiation along the way. Eventually a deal emerged which has polarized both the media and blogsphere between being the salvation of mankind or the quick route to runaway warming. In reality it is neither, but if that is the case then where are we?

First the good news. After years of discussion, stalling and negotiation the Clean Development Mechanism (CDM) is now able to accept Carbon Capture and Storage (CCS) projects. This important technology now has the opportunity for global use under a clear set of rules that all countries have sanctioned. Of course there remains the ongoing issue of the low price of CERs, largely driven by the weakness of the EU-ETS, but at least the CDM will continue to exist thanks to a Durban agreement on the continuation of the Kyoto Protocol, albeit with a limited set of players. If nothing else, the “CCS in CDM” agreement puts CCS properly on the radar and hopefully paves the way for implementation through other means, such as via the Green Climate Fund. 

In addition to the move on CCS, the Green Climate Fund and Technology Mechanism both made useful progress. In comparison to expectations going into Durban, the COP could be regarded as something of a success. But these are small steps to take for a two week conference which attracts some 10,000 people (including observers). Of course the real objective is to make a major step forward and agree a way for all parties to begin rapidly reducing emissions.

What then of the agreement in Durban to negotiate a new protocol (or another legal instrument or a legal outcome) by 2015 at the latest, for implementation by 2020? From the perspective of large scale mitigation action involving all the major emitters, this is good news, but given the reality of the rate of increase in the level of CO2 in the atmosphere, the story is really very different.

In a 2009 posting, I discussed the issue of a 2°C objective on the basis of CO2 behaving like a stock pollutant in the atmosphere (Allen et al, Nature, April 2009). For a 50% chance of limiting the global temperature rise to 2°C, the stock of CO2 should not rise above 1 trillion tonnes of carbon (or 3.667 trillion tonnes of CO2). This provides a useful way of assessing the impact of the “Durban Platform for Enhanced Action”. Consider four cases;

1. The “do nothing” base case which sees emissions continue to rise at the rate of 2% per annum (global emissions increased by 2.5% p.a. over the period 2000 to 2009 – IEA) and accumulate in the atmosphere. This sees the trillionth tonne emitted in 2044 with continued rapid accumulation in the decades following.
2. A dramatic (but of course hypothetical) deal in Durban which sees global emissions peak immediately and begin to fall at 1.7% p.a., the same rate of decline as currently built into the EU ETS. In this case the trillionth tonne is emitted just after 2100, but emissions are very low by this time and still falling, so the 2°C limit is effectively met.
3. Business as usual continues until 2020, but the “Durban Platform” acts aggressively on global emissions post-2020, with emissions peaking in that year and then falling. To achieve the same outcome as Case 2 the annual rate of decline must now be 3% p.a.
4. Business as usual continues until 2020, with the “Durban Platform” resulting in a global plateau in emissions from 2020 to 2030, then falling after that. Now the rate of decline must be over 4.5% p.a. to achieve the same outcome as Case 2. 

While the agreement to start negotiating again with a view towards implementation of a global plan from 2015/2020 must be seen as a positive development, the time lag now built into the process must equally be a cause for concern. There is nothing easy about emissions and the future, but starting the job today is an essential requirement for meeting the 2°C goal – this was also the clear message from the IEA (International Energy Agency) going into COP 17. A theoretical global decline of 1.7% p.a. is at least still within the bounds of technical (but clearly not political)plausibility, although only just, but arguably a reduction rate of 3% or 4.5% is beyond an achievable outcome. Even the financial crisis only managed to deliver a 1.4% reduction from 2008 to 2009 before emissions bounced back in 2010. A 3% p.a. decline from 2020 requires more than a billion tonnes per annum of reduction – or the startup of at least 130 very large CCS facilities that year and then each year after that. A 4.5% p.a. decline is considerably more difficult to achieve.

The above cases 3 and 4 which both represent a robust deal coming from the “Durban Platform” are also very optimistic given the track record of the UNFCCC negotiations and perhaps of greater concern, the track record of national implementation of agreements made.

Nevertheless, Durban may well be seen as a landmark COP and it may just mark the point at which attitudes change, but the shape of the outcome also makes the challenge ahead that much greater.

Last week I went to the London showing of Vice President Al Gore’s Climate Reality Project - it was one of 24 consecutive presentations held around the world on the 15th of September. There was a lot to look forward to in attending this, particularly to see how Mr Gore would respond to the troubling attacks on the science currently seen in some political debates and the continued challenge to carbon pricing policy in countries like Australia. Some have argued that we are at a crossroads in climate policy, with richer nations seemingly deciding that they will wing it and let the physics play out over the coming century (for a thoughtful piece on this click here).

 From a personal perspective and for context, I found An Inconvenient Truth to be a remarkable film and I was very pleased to be able to attend an Al Gore training session myself – and one that he personally delivered for a day in Cambridge, England. I have even used some of the material in my own presentations, which of course was the quid pro quo for attending the training. But it is good material and although I differ with Mr Gore on the way he interpreted some of the paleoclimate record, his overall message was solid.

This time though, I was disappointed and I am even more disappointed that this was the case. The core section of the presentation focused on extreme weather events and pretty much blamed them all on the long term change in the climate that is seemingly underway. By chance that same afternoon, I had listened in to an MIT web cast on exactly the same subject – extreme weather events. For me the contrast between the two was a concern. Although both presentations explained the observable shifts taking place in the global hydrological cycle and both showed the disturbing trend in measurements such as atmospheric humidity, Mr Gore then went straight from that to the remarkable cascade of disasters that have unfolded over the past 12 months. MIT did not, nor would their presenter be drawn on it even when pressed on the subject by one of the listeners. Rather, MIT focused on the rising global temperature and humidity and declining ice coverage and showed real measurements which illustrated how warmer ocean surface temperatures might lead to more intense hurricane activity.

Included within the Climate Reality slideshow were the Pakistan floods, the Australian floods and bush fires, the US floods from North Dakota to Nashville and down the Mississippi / Missouri River system, mud slides in Colombia and the Texas drought. These have been (and continue to be) awful events and they are illustrative of some of the possible impacts of a warmer, moister atmosphere, but they are not necessarily caused by this. In fact, 1974 also suffered a string of such disasters and both it and 2010/11 had another thing in common, an intense La Nina (1973-1975) in the Pacific. Record Australian, Brazilian, Colombian and Bangladeshi floods all featured in 1974, together with a super-outbreak of tornadoes in the United States. Somalia suffered an intense drought in that period as did the central USSR.

I don’t want to undermine the efforts of Mr Gore, but only point out that he is going to have to do better to communicate his important message. In this era of soundbites and media savvy politicians it will be all too easy to take shots at this new work. The much longer but more rigorous MIT approach is where we should be, despite the huge challenge of successfully communicating uncertainty and atmospheric chemistry to a global audience. Let’s not forget that a much more complex atmospheric chemistry issue (CFCs and the ozone layer) was communicated in the 1980’s.

In the last section of the presentation Mr Gore poured scorn on those who have challenged the science. This included special interest lobby groups (oil companies among them) and a number of well known political figures. I can’t agree with the statements made by some leading politicians who dispute the work of the scientific community, but direct attack isn’t the answer here, despite the huge temptation to do so. Nor is it the reality that all industry lobby groups are seeking to undermine the science. While some groups have been less than helpful and others have just displayed ignorance, many, many business groups have positively contributed to the development of a way forward. In the US, USCAP did a remarkable job in helping craft and then supporting the Waxman-Markey bill. Globally, some 150 companies (many of which are Fortune 500) belong to the International Emissions Trading Association (IETA) and actively press for cap-and-trade approaches at national and regional level. Similar work is done in the WBCSD, the UK and EU Corporate Leaders Groups on Climate Change, the European Round Table of Industrialists, just to name a few. Sure, the businesses in these groups might fight their corner and will have no qualms about challenging issues such as allowance allocation in trading systems, but that is in the nature of reaching agreement.

The Climate Reality Project is an important next step, but at the moment it feels like a somewhat inconvenient one. The challenge back is the right thing to do, but the debate needs to be moved to a higher level, out of the trenches that currently seem to be occupied by many. This is an issue that will be around for the next 100 years and possibly much longer. We will all be too exhausted to even think about a true response if the current level of rancor is simply maintained.

It has been an interesting week for climate change news, with the IPCC releasing its full report on renewable energy, the European Commission moving ahead with energy efficiency legislation, very little happening at the UNFCCC talks in Bonn and of course the battle over carbon pricing continuing in Australia. In scanning the Australian media I spotted an insightful interview with the United States Ambassador to Australia. In the interview, Ambassador Bleich argues that the USA is on track to meet its 2020 greenhouse gas target (17% below 2005 levels) because of the breadth of activity across the economy in transforming the energy system.

 THE US ambassador to Australia says America is pulling its weight in international efforts to reduce greenhouse emissions, contrary to suggestions a carbon tax would see Australia acting ”ahead of the rest of the world”. In an interview with the (Sydney Morning) Herald, Ambassador Jeff Bleich said the idea that America was lagging was “not accurate at all” and it was “absolutely realistic” to believe the US would meet its target of a 17 per cent reduction in emissions by 2020, based on 2005 levels.

“The US is taking dramatic action, if you look at the largest investment in history in energy transition, the major regulatory reforms for the largest emitters and consumers of energy, the focus on the dirtiest emission technologies used by power plants and vehicles … we are moving on a very aggressive regulatory effort,” he said. “… there’s absolutely no question the United States has been doing a tremendous amount over the last two years … and going forward the President has said we need to double what we are doing because that is good for our economy.”

The Californian emissions trading scheme, due to start next year, could also have “dramatic effects”, for that state and potentially on a broader scheme for the western states of the US and Canada, he said. Although President Obama had been clear he preferred a national cap and trade scheme, when that was not successful in Congress he had moved to different approaches. These had not put the United States at a competitive disadvantage with major trading partners because China, Europe and others were taking action as well, nor had US companies in Australia expressed concern that a carbon tax would disadvantage their business here.

The Australian Industry Greenhouse Network has cited figures from the US showing that because of the impact of the financial crisis, US emissions were not scheduled to return to 2007 levels until 2027, suggesting that the US emissions reduction target was now easier and no longer required an “equivalent effort” to Australia’s emissions reduction target of a 5 per cent cut based on 2000 levels.

Ambassador Bleich said that while the financial crisis may have had an impact on emissions, the measures being taken by the administration were also having a real impact.

The recent Productivity Commission report said the US was spending a little less than Australia on reducing emissions as a percentage of GDP and was abating less from its electricity sector, but Ambassador Bleich said the report had provided more evidence that major emitters were all acting.

I have discussed this before, but it is worthy of a revisit. There is no question that US emissions have fallen in part as a result of the recession, but the increasing availability of natural gas and generally higher energy prices causing consumers to think about energy use are also having an impact. Furthermore, a variety of renewable energy programmes (but mainly wind) are filling in capacity gaps in the power market and the Bush Administration bio-fuel mandates are having an impact in the road transport sector.

I recently revised my own analysis of US emissions for a conference and developed the following summary picture:

In terms of progress from today, the two big ticket items remain natural gas substitution for coal and the impact of CAFE standards in the transport sector. Emission and water regulation (not including GHGs) under the Environmental Protection Agency (EPA) could result in a substantial portion of US coal fired power generation shut down by 2020. The displacement of up to 70 GW of coal fired generation capacity would require about 7.8 Bcf/day of natural gas or some 4 years of production increase, assuming the current production trend is maintained. Even if the annual increase was half the current trend, sufficient additional production would be available for such large scale substitution over the period 2012-2020.

The real unknown of course is the possibility of an emissions upswing over this decade as the economy shifts back into full gear.

US success in meeting the 2020 target could profoundly affect the broader discussions on reducing CO2 emissions, both in the USA and more widely. After 2020 we might we see more acceptance of CO2 measures on the basis that emissions had fallen, it hadn’t damaged the economy or society, so “we can then do more”. But it could be a double edged sword, with complacency creeping in on the back of the argument that the market has responded and CO2 is taking care of itself, so there is no need to worry about it.

Sitting on a beach in Italy with my family leads to all sorts of bizarre conversational directions. My 15 year old son and I were filling some time by challenging each other to estimate things based on scant information and assumptions. Having just figured out that the volume of the ocean was some 1.4×10^21 litres (we were surprisingly close as it turned out) we turned our attention to the number of boxes of Cornflakes sold in the UK each week (yes, this is going somewhere).

Assuming a population of some 60 million of whom 60% eat breakfast cereal and of those 10% eat Cornflakes, we ended up with 3.6 million servings a day. If an average box lasts 10 days then that comes to some 2.5 million boxes per week.

The next challenge was to estimate how much energy is used in just moving Cornflakes from the point of production to the point of purchase in the UK. We started by assuming that an average distribution truck (accounting for both big supermarket and smaller shop distribution) would have a capacity of 4 x 2 x 2 metres or 16 m3. If a box is 40 x 25 x 7 cms or 7000 cm3 then a truck could carry about 2000 boxes. That means 1200 truck loads of Cornflakes per week.

We then assumed that on average a purchase point is no more than 100 miles from a production point so that the average box of Cornflakes travels 50 miles at a minimum (I suspect it may be somewhat higher than this). If an average truck gets 10 miles per gallon then moving Cornflakes in the UK consumes 6000 gallons of fuel per week or about 150 barrels of oil (about 10p for each customer per year). That adds up to some 8000 barrels per annum which in turn adds nearly 3000 tonnes of CO2 to the atmosphere.

None of this may sound much, but don’t forget that we are just moving Cornflakes (no other cereal) from the point of production to the point of purchase in the UK only ! One tiny aspect of our lives.

Food for thought !

Although the airspace is now open again, it has been impossible to be in the UK this week and not hear about, talk about or watch volcanoes. It has also made everybody painfully aware of the fact that we are totally and utterly dependent on air travel and that having a global air travel hub on a small island presents a further set of complications when the system doesn’t function as it should. Not only have travelers been stranded, but the impact was quickly felt by the likes of Kenyan flower growers and market gardeners – although this was apparently solved fairly rapidly as air freight was diverted to Spain and supermarkets trucked from there.

Arguably we have been really unlucky – a combination of location (near major air routes), timing (end of Easter vacation) and weather patterns (a huge blocking high pressure system) has made this event particularly traumatic for those directly impacted. But for those of us in London with no travel plans, the reverse has been true – nice weather, much less traffic near Heathrow and quiet skies. Even BAA, the company which owns and operates Heathrow has had its own small silver lining in this cloud of ash – apparently they have used the time to collect baseline environmental data around Heathrow which will help them better understand the local impact of aviation.

As readers of climate literature will doubtless know, volcanoes have figured heavily in global climate over the millennia. There is evidence in the paleoclimate  record that they may have contributed so much CO2 to the atmosphere in periods of extended high activity that warming occurred as a result. On a shorter timescale they also contribute to cooling of the atmosphere due to the discharge of large amounts of ash and sulphur compounds.

Whilst the current eruption is turning out to be very disruptive, compared to other eruptions in history it is a mere puff of smoke. Eyjafjallajokull has ejected about 140 million cubic metres of material, but Pinatubo (the Philippines in 1991) ejected 10 cubic kilometres – that’s 100 times as much and Tamboro in Indonesia ejected 160 cubic kilometers in April 1815. The super-volcano which still exists under Yellowstone National Park has the potential to eject at least an order of magnitude more than this – but with no expectation that it will do so anytime soon.

Even in recently recorded history there is evidence of the short term climate effects of volcanic eruptions. 1816, the year after Tamboro, was known as the “year without a summer” in Europe and another Icelandic volcano that erupted in 1783-1784 apparently impacted life in Northern Europe, parts of Asia and Africa and in Iceland killed over half of livestock followed by a famine in which a quarter of the population died. In the following years there were crop failures and record grain prices in France (this may of course be unrelated). Looking at the UK monthly temperature record for the past 400 years it is possible to see some of this (but there are also plenty of years with anomalous data in which there was no volcanic activity). The chart below shows yearly data from 1650, with the blue data being the annual average temperature, the yellow data being the maximum monthly average for a given year and the purple data the minimum monthly average for that year. The trend lines show the current warming and give some hint of the Maunder Minimum in the second half of the 17^th Century.

Looking at the Tamboro event more specifically, the chart below shows the monthly average temperature as a difference to the average for that month for the period 1650 to 2008. 1816 does appear to be well below the average and is generally lower than the surrounding years.

In terms of CO2 impact, the grounding of thousands of flights has led to some newspapers here in the UK commenting on the CO2 impact. The Times calculated that some 1.5 million tonnes of CO2 emissions had been avoided (based on the premise that on a normal day the 28,000 flights in European airspace emit about 560,000 tonnes of CO2). This led me to wonder why they hadn’t included the CO2 impact of the volcano itself – there seem to be a number of different figures for this but all are less than the CO2 impact of European aviation itself and some considerably less.

 Meanwhile, con-trails are again visible over London and that almost ever present background noise has returned.

It isn’t often that you actually see something that surprises you and makes you really think about what is happening to the climate. I am in Washington, D.C. at the moment and flew here yesterday. We passed over Newfoundland and the southern part of the Gulf of St Lawrence on the way into Washington. I had a right hand side window seat and the all the way from Newfoundland to the Canadian mainland there was blue sky and crystal clear visibility for miles.

As we passed over Newfoundland I was thinking that it didn’t   appear quite as white as normal, with very visible features showing. I have passed over this region many times in the winter and on the few cloudless days that there are I can only ever recall it being just a total whiteout. On the south western coast of Newfoundland (St George’s Bay) there are mountains at the shore and these had a very clear snowline at quite a high level, rather than my expectation that it would be white to the coast.

But the real surprise was passing over the Gulf of St Lawrence – there was no pack ice on the water at all as far into the distance as I could see. It was just blue to the horizon. I know that the St Lawrence Seaway ices up in winter and of course this winter, al least in the United States, will be remembered for its severity, but it certainly didn’t appear so severe in this part of North America.

Not being sure if my observation is unusual or not, I have looked on the web and found a NASA link which shows the same area in April 2008. This is later in the year and it seems to show quite a bit of ice. (http://earthobservatory.nasa.gov/IOTD/view.php?id=8661).

I won’t jump to any conclusions here, but I did want to share my own observation.

Meanwhile, it was snowing again in Houston!!!

In recent weeks as the IPCC has revealed a number of misquotes in their 4th Assessment Report and with the UEA e-mail issue rumbling on, climate science has come under intense scrutiny. A couple of weeks back I commented on the way in which we all seem to love technology, but at the same time society is becoming increasingly uneasy with science.

As has been the case over the many years of this issue, the media is also playing a role. In the past we have often seen reports of apocalypse and whilst many of these reports had a basis in science, they sometimes reported one extreme end of the spectrum of potential outcomes. Today, it is climate science that is undergoing a similar treatment. Late last year the Daily Express compiled its “100 Reasons Why Global Warming Is Natural” (http://www.dailyexpress.co.uk/posts/view/146138), first published during Copenhagen but now rolled out again in the context of the start of the government enquiry into the University of East Anglia e-mail break-in. Like the stories of apocalypse, it could make the reader think that the scientific basis for anthropogenic warming had utterly collapsed. But on closer scrutiny the 100 reasons don’t present a reasoned arguement to believe that everything has suddenly changed.

Let me illustrate: In the region of half of the statements, whether true or not, have no bearing on the relationship between increasing greenhouse gas levels in the atmosphere and recorded warming over the last 100 years (e.g. India plans to reduce the ratio of emissions to production by 20-25% compared to 2005, but all government officials insist that since India has to grow for its development and poverty alleviation, it has to emit, because the economy is driven by carbon). Then there are numerous statements which are just that, statements, with apparently no quoted evidence or substantiation. For example;

Statement 2 argues that man-made carbon dioxide emissions throughout human history constitute less than 0.00022 percent of the total naturally emitted from the mantle of the earth during geological history. This may well be the case, but has no bearing on the fact that we have added nearly 2 trillion tonnes of CO2 and other greenhouse gases to the atmosphere in just 200 years and that this has been sufficient to see a marked shift in the CO2 levels in the atmosphere today.

Statement 7 argues that the 0.7C increase in the average global temperature over the last hundred years is entirely consistent with well-established, long-term, natural climate trends. The problem here is that this has been shown not to be the case. Page 11 of the Summary for Policymakers (Fourth Assessment Report) of the report of Working Group 1 of the IPCC shows that both natural and anthropogenic forcings need to be applied to explain the changes in temperature over the 20th century. No other approach consistently matches the observed data.

Statement 15 argues that it is absurd to accuse a single trace gas of radically changing the climate. But the IPCC makes it abundantly clear that climate change is the result of many anthropogenic forcings, including CO2, other trace gases, aerosols and changes in cloud cover (e.g. contrails from aircraft). However, there is also clear evidence that CO2 is a very important forcing component in the atmosphere.

Whilst every media outlet and every person is more than entitled to express an opinion, and I welcome the debate, we urgently need to raise the level of the debate and understanding of climate science. There is little doubt that much is still to be learned about this great physics experiment we are undertaking in our atmosphere by changing its composition. Perhaps warming will proceed dramatically over the next few decades, but there is a chance other factors might just supress everything for a while and leave us in a state of complacency. Either way, we can’t actually be certain today, but we can go some way to quantify the risks that we are running. This is where much of today’s scientific study is focussed. Shell sponsors MIT’s Joint Program on the Science and Policy of Global Change which undertakes such risk analysis.

More to the point, the complication with this issue is that we have to act before we can be absolutely sure of the outcome. If we don’t act and it transpires that the outcome is not something the world likes, there is then no going back. This means that society needs to both understand the science and come to terms with the risks that it shows we are collectively running.

As an Australian living in London and subject to the market forces that an emissions trading system brings to the economy, I watch with great interest as Australia wrestles with the Carbon Pollution Reduction Scheme (CPRS), or “cap-and-trade” by another name (or emissions trading by another).

Since Kevin Rudd became Prime Minister just days before the Bali UN Climate Change Conference in 2007, he has ratified the Kyoto Protocol and tabled legislation to introduce an economy wide cap-and-trade system. The legislation has passed through the House of Representatives but is now stuck in the Senate where the Rudd government does not have a working majority. Over recent weeks the government has been negotiating with the leading opposition party to try and find a workable consensus and deliver the bill before Copenhagen.

This week that failed spectacularly. The nature of the legislation has also split the conservative opposition, with the result that the parliamentary leader of the party was deposed by a one vote majority and the new leader, Tony Abbott, has now made it clear that no immediate deal will be done and as expected, the legislation has now been rejected by the Senate. This potentially paves the way for a double dissolution of parliament and what could truly be the world’s first “climate change” election, although the government has indicated that it will reintroduce the legislation in February after Copenhagen and the summer recess of parliament. Abbott has also been labelled by some media outlets as a “climate sceptic” .

Australia has seen a number of weather extremes in recent years. A prolonged drought has brought despair to much of the rural sector, water restrictions are now common in places such Adelaide, temperatures in Melbourne hit a record 47 degrees C last February, the list goes on. Whilst all or none of these may be related to a changing climate (and Australia is a country of climate extremes), there is little doubt that they have raised the awareness of the issues we may all face in the decades to come. Both party leaders now claim the ear of the public on the issue, with the government arguing that the majority of Australians want to see the country act on climate change and the opposition leader claiming that the majority of Australians are opposed to the cap-and-trade legislation. Contrast all this with the reality that, according to the International Energy Agency, Australia has the highest per capita emissions in the world (apart from a handful of countries with small populations and a particular concentration of industry). It is also a country with huge solar resources, significant wind opportunity, ample uranium and over the last few years a very aggressive development programme for carbon capture and storage.

Whilst there will doubtless be short term political winners and losers in Australia, the real issue here is that there may be significant impairment to the long term policy solution set for managing emissions - with cap-and-trade at the heart of it. In turn, the environment itself suffers as widespread policy action is weakened. The development of a global carbon market, built by linking together various national trading schemes, is arguably where the world needs to go. Energy pricing is global, so injecting a carbon price into the mix will, over time, deliver change at a global level. Whilst there are many ways of creating a carbon price, cap-and-trade is designed to do it through a market based approach at lowest cost to the economy – things that should be attractive to legislators in market based economies.  It’s really that simple, although as Australia is showing, simple is not always as simple as it seems.