How Hard Would Dramatic Greenhouse Gas Emissions Reductions Really Be?

As the New Zealand Government consults on a greenhouse emissions reduction target for New Zealand we are often treated to a talking point along the lines that a 40% reduction at 2020 is "obviously" not feasible. This is always coupled with pointing out that 40% means a 40% reduction on 1990 emissions and that's a 60% reduction on today, and yes Labour was in power for much of the intervening period and what a debacle that was and so on and so forth.

Here's Kiwiblog's latest on the subject for example, and Matthew Hooton gave stirring rendition on Nine to Noon on National Radio during last week.

I had some sympathy for this view, and certainly if DPF or I, neither of us with any relevant qualifications, spend a few seconds perusing New Zealand's emissions profile, it does seem a pretty tall order to reduce greenhouse gas emissions by 60% over a decade.

Allow me to point to a remarkable recent Australasian efficiency achievement as a corrective to this pessimistic view.

Many of you will know that south-east Queensland has just emerged from a prolonged drought. At its lowest point the dams that store Brisbane's drinking water were at just 17% of capacity. As a result the Queensland Government initiated a series of water restrictions and water efficiency campaigns.

Prior to the drought per capita daily water consumption in south-east Queensland was pushing 300L. Three years later at end of the drought it was down around 130L.

That's right, domestic water consumption in south-east Queensland was reduced by more than 50% in just three years! Look at the figure, from the official report here. (Click on the figure to read it clearly.)



And what is residential water consumption in south east Queensland today, roughly a year after the end of the drought? 140L per person per day. 120L if it's school holidays.

This goes to show that dramatic and permanent efficiency gains are possible if there is the public and political will to make them. You really have to ask yourself if it is that much harder to reduce our dependence on greenhouse gas emissions than it is to reduce water use? (There are some obvious possibilities but that's for another post.)

I've said it before and I'll say it again, efficiency gains are the first and cheapest way to make reductions in greenhouse gas emissions. And the sooner big business stops paying lobbyists to derail change and starts paying engineers to work out how to solve the problem, the better.

The ideas in this post are shamelessly stolen from a recent lecture by Professor Juerg Keller. The line about engineers is likewise stolen from US Secretary of Energy and Physics Nobellist Steven Chu.

Shock! Antarctic Sea Ice is Growing!

The Australian was so full of climate change contrarians on Saturday that it was hard to know where to start. But since both Roarprawn and Whaleoil have pointed to this article on Antarctic ice the problem is solved.

This is a particularly easy instance since the main factual claim made in the article is true. (Not always the case in discussions of climate issues that you find in the newspaper!) It just happens not to say much one way or the other about global warming.

East Antarctica is four times the size of west Antarctica and parts of it are cooling. The Scientific Committee on Antarctic Research report prepared for last week's meeting of Antarctic Treaty nations in Washington noted the South Pole had shown "significant cooling in recent decades".

Australian Antarctic Division glaciology program head Ian Allison said sea ice losses in west Antarctica over the past 30 years had been more than offset by increases in the Ross Sea region, just one sector of east Antarctica.

"Sea ice conditions have remained stable in Antarctica generally," Dr Allison said.

This is not a "climate change lie exposed" as Whaleoil claims, scientists have known this for a long time and have said so. Now we just have better data. It is not even clear to me that there is "a widespread public belief" that Antartic sea ice is contracting as the article claims. (The Arctic is of course another matter, and maybe many confuse the two?)

Why does increasing Antarctic sea ice not challenge current scientific thinking about global warming? I'll defer to the US agency the National Snow and Ice Data Center

Another important point is that the increase in Antarctic sea ice extent is not surprising to climate scientists. When scientists refer to global warming, they don’t mean warming will occur everywhere on the planet at the same rate. In some places, temporary cooling may even occur. Antarctica is an example of regional cooling. Even our earliest climate models projected that Antarctica would be much slower in responding to rising greenhouse gas concentrations than the Arctic. In large part, this reflects the nature of the ocean structure in Antarctica, in which water warmed at the surface quickly mixes downward, making it harder to melt ice.

In terms of sea ice, climate model projections of Antarctic sea ice extent are in reasonable agreement with the observations to date. It also appears that atmospheric greenhouse gases, as well as the loss of ozone, have acted to increase the winds around Antarctica. Perhaps counter intuitively, this has further protected the Antarctic from warming and has fostered more ice growth.

The one region of Antarctica that is strongly warming is the Antarctic Peninsula, which juts out into the Atlantic Ocean and is thus less protected by the altered wind pattern. The Antarctic Peninsula is experiencing ice shelf collapse and strongly reduced sea ice.

Why are scientists very concerned by reductions in Arctic sea ice but don't seem to talk much about Antarctic sea ice?

Unlike Arctic sea ice, Antarctic sea ice disappears almost completely during the summer, and has since scientists have studied it. Earth’s climate system over thousands of years has been "in tune" with this annual summertime disappearance of Antarctic sea ice. However, satellite records and pre-satellite records indicate that the Arctic has not been free of summertime sea ice for at least 5,500 years and possibly for 125,000 years. So Earth’s climate system and ecosystems, as they exist today, did not develop in conjunction with an ice-free Arctic. Such an ice-free Arctic summer environment would be a change unprecedented in modern human history and could have ramifications for climate around the world.

Economic crisis to delay U.S. carbon trading?

In more recent comments Chu is open to considering a carbon tax, rather than cap and trade, a good thing perhaps.

More importantly perhaps he seems to indicate that the current economic crisis will delay either cap and trade or other carbon pricing mechanisms.

He said that while President Obama and Congressional Democratic leaders had endorsed a so-called cap-and-trade system to control global warming pollutants, there were alternatives that could emerge, including a tax on carbon emissions or a modified version of cap-and-trade.

Dr. Chu said reaching agreement on legislation to combat climate change would be difficult in the current recession because any scheme to regulate greenhouse gas emissions would probably cause energy prices to rise and drive manufacturing jobs to countries where energy is cheaper.

“The concern about cap-and-trade in today’s economic climate,” Dr. Chu said, “is that a lot of money might flow to developing countries in a way that might not be completely politically sellable.”

Chu Back to Speaking His Mind

It's great to see Nobel Prize winning physicist and U.S. Energy Secretary Steven Chu back to speaking his mind. Here from an interview in the L.A. Times he discusses the effects of reduced snow-pack on California.

In the pessimistic scenario, the snow pack will decrease by 70 to 90 percent. Well, let me tell you what California does when there's a two-year in a row 20 percent decrease in snow pack: They water-ration.

Q: So you're looking at a scenario of permanent water rationing?

CHU: No, you're looking at a scenario where there's no more agriculture in California.

You may have noticed that during his confirmation hearing he walked back an earlier comment that coal was his "nightmare", describing it only as a bad dream, (NYTimes) but maybe one only needs to be circumspect in front of the Senate committee?

In the L.A. Times interview Chu presents the case for action against climate change despite uncertainties in our knowledge. He has a particularly good analogy to the dangers of old electrical wiring.

Carbon dioxide is a global problem. The cost of the carbon emissions are things that, number one, won't show up immediately in one year, or even in 10 years. They have begun to appear. The real costs are hard to estimate because we don't know to what extent, how bad it's going to get, in all honesty. There are projections... You can make a best guess on what might happen. I prefer - there are people who say, since we're not sure, we really shouldn't do about it - I think, in my opinion, a more measured way of dealing with this is, it's all about the risk, the potential risk, the downside risk of not doing something, or maybe doing it in a very moderate way.

The analogy I like to use is, suppose you buy a house, and then in the inspection, the structural engineer says, well, this House is a fine house, but understand, you have to rewire the house, because it's an old wiring and there's a chance of an electrical fire. It's going to cost a lot of money, but you should rewire... So you get an estimate of whether you really need to rewire the house, or whether you can go another, safely for another 20 years or 10 years. Suppose, just pretend, that the next person comes and says, essentially, I think the wiring is shot. I can't guarantee if it's going to be this year or five years from now, but you run the risk of an electrical fire. So now you have many options. You can continue to shop for the answer you want: your house is safe. Or you can say, I know the solution.... let's pretend it's $20,000, a lot of money, that's going to come out of your budget, an you can't - you're going to have to forgo a lot of other things. You could say, well, I could just get better fire insurance. You're probably not going to do that. Because there's a chance the house could burn down when you're asleep and your kids are asleep in the house. So eventually, you might be led to say, if there's a 50 percent chance my house might burn down in five years, I better do the rewiring. Then you have to bite the bullet. No one is telling you there's a 100 percent chance this is going to happen.

Finally this

Dr. Chu said he was still adjusting to his surroundings and title after most of a career spent as an academic scientist. Asked whether he preferred to be called “Dr. Chu” or “Mr. Secretary,” he answered, “Steve is fine.”

Given what I have heard about the workrate Chu expects, I wonder if some at the Department of Energy will be in for a period adjustment also.

U.S Coal Reserves

I've noted before that people such as David Rutledge at Caltech and the Energy Watch Group believe that economically extractible world coal reserves are enormously overstated. Rutledge believes the situation is sufficiently serious that it will ultimately limit CO2 emissions to below the IPCC scenarios.

The EWG has emphasized the enormous writedowns in recent years of coal reserves by many countries, who have been motivated to look into the matter by declining coal production.

Climate Progress notes that the United States Geological Survey have finally joined this trend. They have done a thorough analysis of a single coal field that provides 37% of U.S. coal production.

Coal reserves are the portion of the recoverable coal that can be mined, processed, and marketed at a profit at the time of the economic evaluation. With a discounted cash flow at 8 percent rate of return, the coal reserves estimate for the Gillette coalfield is 10.1 billion short tons of coal (6 percent of the original resource total) for the 6 coal beds evaluated.

In 2006 production at the Gillette coalfield was 436 million short tons or 4% of the economically extractible resource. Unsurprisingly then that the National Research Council is calling for research into the size of reserves.

It is clear that there is enough coal at current rates of production to meet anticipated needs through 2030, and probably enough for 100 years, the committee said. However, it is not possible to confirm the often-quoted assertion that there is a sufficient supply for the next 250 years.

The report recommends a federal-state-industry initiative to determine the size and characteristics of the nation's recoverable coal, with the goal of providing policymakers with a full account of these reserves within 10 years. The initiative should be led by the U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy's Energy Information Administration, states, and industry, and will require additional funding of approximately $10 million per year.

The group Clean Energy Action has just released a pessimistic report on U.S. coal.

In an extensively resarched report using publicly available data, Clean Energy Action member Leslie Glustrom says "we were quite shocked to find that most of the coal in the United States is buried too deeply to be accessible in large quantities or at reasonable prices."

Assumptions about the cheap price of coal figure critically in utility planning decisions including the option to choose renewable energy to generate electricity.

She documents that US coal supplies are not in the 200 year range as commonly assumed, but more likely in the 50 year range. Key supporting data includes a US Geological Survey report - Open File Report 2008-1202 - indicating that only 6% (or about 10 billion tons) of the original coal resource in the Gillette Coal Field of the Powder River Basin of Wyoming is economically accessible.

The Australian Liberal Party and Agricultural Greenhouse Gas Emissions

Yesterday Australian Liberal Party leader Malcolm Turnbull gave an interesting speech on climate change policy to the Young Liberals conference. The associated change in policy direction was leaked to the Saturday newspapers, here for example.

Turnbull has been under pressure from the Nationals who are opposed to an emissions trading scheme. As a result we get this:

The Opposition Leader, Malcolm Turnbull, will announce a three-pronged policy of greenhouse gas reduction that will impose no direct costs on businesses or homes and require no behavioural change, and aims to eradicate divisions in the Coalition over climate change.

It's astonishing that a serious response to climate change can be advertised as requiring "no behvioural change" but there you go.

The speech itself is interesting, with three major policy proposals.

Our plan captures three gigantic opportunities for CO2 abatement that the Rudd Government has ignored:
· A Green Carbon Initiative - a comprehensive biocarbon strategy ofinvesting in the health of our landscape, restoring soil carbon by reversing over-grazing and excessive tillage, embedding CO2 in biochar (charcoal fertiliser), tree planting, and revegetation;
· Dramatically increasing energy efficiency, especially in buildings;
· Constructing at least two industrial scale carbon capture and storage power stations deploying industrial scale solar energy and geothermal energy and harnessing the energy of the oceans through tidal and wave power.

The Green Carbon Initiative aims to address the issues of terrestrial carbon sequestration discussed in my previous post. Turnbull has been talking to serious people about this and the measures he proposes seem worthwhile. Of course the small matter of the structure of the incentives in the Kyoto protocol and its successors needs to be addressed so that Australia gets full credit for any moves in this direction. It's hard to know how to weigh the contributions of serious thought and political opportunism in this proposal.

As to the second point, increased energy efficiency should be the FIRST priority of policy makers and politicians in response to the twin challenges of climate change and the need for economic stimulus. Here I would fault Turnbull only for inappropriate emphasis.

His third point which mainly emphasizes carbon capture and storage at coal fired power stations needs a serious caveat. CARBON CAPTURE AND STORAGE IS AN UNPROVEN TECHNOLOGY. On the other hand the various sources of alternative energy generation are already technologically feasible and even economic in the right circumstances. Again the emphasis is all wrong.

Finally the implication that the Rudd Government is not thinking about any of these approaches seems a little unfair!

Nevertheless the politics of climate change and emissions trading in Australia look to be very interesting in the coming year.

Things I've Learnt About Agricultural Greenhouse Gas Emissions

While on holiday on in Nelson I engaged in some blogging back and forth with Charles Finny at Dear John on the subject of agricultural greenhouse gas emissions and Kyoto.

Since then I have been trying to get up to speed on some of the questions we discussed so as to reach a non-holiday, informed, opinion on the issues.

One good resource for information is the UN Food and Agriculture Organisation's 2006 report Livestock's Long Shadow. Despite being a product of the dreaded UN, and one that has come in for some political criticism, this seems to me a generally informative and well referenced report. In particular Chapter 3 addresses agriculture's impact on the carbon cycle.

Firstly: we spent some time on arithmetic. Charles wanted to estimate the savings if agricultural methane emissions were discounted under the assumption that every atom of carbon in emitted methane originated from grass that had recently absorbed CO2 from the atmosphere due to photosynthesis. This resulted in a reduction in CO2 equivalent emissions equal to about 10% of agricultural methane emissions.

Whatever the merits of the premise I would argue that this shows that New Zealand policy makers should pay very close attention to the provisions related to agriculture in any Kyoto successor with a view to improvements that could also constitute significant savings to the New Zealand taxpayer. And it goes without saying that more attention could probably have been paid in the negotiation of the original treaty.

Finally on this point I'll just mention that Kyoto apparently regards the CO2 emissions from livestock respiration as being offset by the CO2 absorption of the grass they eat but charges in full for methane emissions from enteric fermentation and the decomposition of dung. This is addressed in section 3.2.2 of the report.

That said, I still don't know what is wrong with the argument that every C atom in CH4 emitted by livestock also originated in CO2 recently absorbed by the grass they ate.

Secondly: this discussion assumed farming was going on in a steady state. The report highlights the fact that land use changes, in particular cutting down forests for agriculture, result in much of the carbon emissions related to agriculture. Deforestation in New Zealand in favour of dairy farming has been a significant source of carbon emissions as we all know.

Thirdly: on a related point we also ignored the fact that farm land, like forests, can be significant carbon sink and the stored carbon can be increased by appropriate farming practices. It's estimated that one quarter of the international response to climate change could involve storing carbon on land (terrestrial carbon sequestration). Of this it seems that about a third could be carbon storage in agricultural land rather than new forests or avoided deforestation. (For information about this you should take a look at the recent Lowy Institute talk by Ralph Ashton, video here and podcast from the Lowy Institute.)

Typically the conversion of natural ecosystems to agriculture results in the loss of 20 to 50% of the stored organic carbon in the top metre of soil. However there is evidence that at least 50% of this lost carbon storage can be restored by appropriate farming practices. These include agricultural intsensification, conservation tillage and erosion reduction. This is discussed in section 3.5.1 of the FAO report. It seems that Professor Rattan Lal at the University of Ohio is at least one of the world experts on this and those of you with access to a Science subscription may be interested in his review article on soil carbon sequestrtion, global warming and food security.

The hook here is that, unlike sequestration in forests, avoided deforestation and agricultural sequestration are not included in Kyoto. So while they have a positive effect on climate change they do not contribute to a nation's responsibilities under Kyoto. A high level group the Terrestrial Carbon Group, which includes Nobel Prize winning economist Joseph Stiglitz and Australian environmental scientist Tim Flannery, have a proposal for how to fix this in any Kyoto successor. This proposal is discussed in Ashton's talk.

Surely if the New Zealand government wishes to put flesh on the bones of its statement at Poznan it should be advocating for efforts like this and in particular a fuller accounting of agricultural emissions and carbon storage?

Agriculture and Kyoto

Most scientists would argue that the Kyoto agreements have many serious deficiencies but are the only framework we have for international efforts to curb greenhouse gas emissions and minimize the risk of catastrophic, or just very damaging, climate change.

From New Zealand's point of view the most serious questions about Kyoto and its successor agreements relate to the impact of agriculture on greenhouse gas emission.

Readers of this blog, if there are still any, might like to take a look at my discussion about some aspects of this with Charles Finny over at Dear John.

Political Emissions

The soft Australian target of a 5% reduction of year 2000 emissions by 2020 has been received with dismay in many quarters. The various corporate hand-outs for "trade exposed emissions intensive industries" along with various offsets for the consumer that look like yet more middle class welfare, also seem pretty unappealing to me. The whole point is supposed to be to create economic incentives to reduce emissions and achieve increases in growth while reducing carbon dioxide emissions per dollar of GDP. This scheme looks to be minimizing those incentives at every turn.

I don't agree with everything there but Anna Rose has a good summary in New Matilda. There have been dramatic shifts since the Green paper, for example

It's worth noting that LNG companies like Woodside and Santos are huge winners from the scheme, as they had been excluded from receiving assistance in the Government's Green paper in July. Now, they'll receive 60 per cent of their permits for free, despite being well positioned to make windfall gains from emissions trading since LNG is a less polluting fuel than coal and oil.

Writing in the Australian Financial Review, John Quiggin, takes issue with the Garnaut/Rudd-Labor argument for low per-centage but high per-capita emissions reductions. The AFR has some pernicious new trick though that stops me cutting and pasting the most apposite part. Shame!

Australasian Contributions to International Climate Change Negotiations

While we await Kevin Rudd's statement on the Australian Government's carbon emission targets on Monday, much attention has turned to the international negotiations on future climate change agreements.

Ross Garnaut wrote a very useful op-ed in the Australian this week. He notes that these negotiations will be much more difficult than either trade or arms control agreements, and proposes some warning signs for difficulties in such talks.

If you hear negotiators from the respective countries arguing that Australia needs high per capita entitlements because it is big and lightly populated, or Canada because it is cold, or Japan because it has few opportunities for geo-sequestration of emissions from fossil fuel combustion, or China because it is the workshop of the world, you will know that the world has lost the battle to avoid dangerous climate change.

It's a cheap shot but I can't resist pointing out that some of New Zealand's statement in Poznan sounds exactly like this

New Zealand is unique among Annex 1 countries. With nearly 50% of our total emissions coming from agriculture, no other developed country comes close to having such a large percentage of its emissions arising from food production.

(Hat-tip: Charles Finny)

Given the ACT party's clutch on climate change policty, some aspects of the New Zealand statement were reassuring. But would Rodney Hide agree with this?

As a consequence we are reviewing our suite of climate change policies. The objective here is not to step back from Kyoto. The Government fully understands and accepts its long-standing international obligations under Kyoto for the first commitment period.

Prior to the election Hide stated his preference for leaving Kyoto.

In any case, Garnaut has become convinced that the eventual target for international negotiations must be equal per capita emmissions from all nations, and that progress should be measured in terms of per capita emissions reductions rather than reductions of particular nations or groups of nations from benchmarks in 1990 for example. This seems pretty sensible to me.

I was happy to see the mention of research on agricultural emissions mitigation in New Zealand's statement, and the emphasis on forms of agreement that will be satisfactory for developing nations. These aspects are very consistent with Garnaut's thinking about ways in which developed countries can contribute initially.

My work on The Garnaut Climate Change Review (Cambridge University Press, 2008) has led me to the view that any allocation of emissions entitlements with a prospect of being accepted by most developing countries must be based on convergence towards low levels of per capita entitlements at some time in the future. There will need to be headroom for rapidly growing developing countries. Through a transition period, the commitments of lower-income developing countries would be one-sided, with compliance encouraged through incentives rather than penalties.

The agreement over emissions entitlements would need to include developed country commitments to public support for research, development and commercialisation of low-emissions technologies. The agreement could embody firm commitments by developed countries to cover additional development assistance for complying developing countries to adapt to the climate change that will inevitably be faced in the period ahead. It could be supported by a proposal for World Trade Organisation rules to constrain individual countries' measures to restrict trade with countries that are not reasonably complying with the requirements of an international mitigation effort.

At the centre of the agreement would be an understanding on the allocation across countries of a diminishing total of annual emissions entitlements. These would be allocated on the basis that emissions would converge towards equal per capita entitlements at some time in the future.

The difference between the basis of allocation of emissions entitlements proposed here, and the Kyoto approach of fixed but differentiated reductions, is large. Within principles designed to reduce global emissions through convergence over time towards equal per capita entitlements, a reduction of 10 per cent from 2000 levels by 2020 in Australia would represent a full proportionate contribution to a global effort to hold concentrations of carbon dioxide equivalents to 550 parts per million. It would represent a larger per capita reduction than was required of the US or the European Union. It would represent a larger per capita reduction for Australia than the EU's implementation of its proposed unconditional commitment to reduce emissions by 20 per cent from 1990 levels.

Select committee terms of reference

It seems that since the order paper was published earlier in the week the following clause has been added to the terms of reference for the climate change select committee

identify the central/benchmark projections which are being used as the motivation for international agreements to combat climate change; and consider the uncertainties and risks surrounding those projections

Good on you Rodney! And a great performance on Morning Report this morning, arguing as usual that there is no rational evidence for human impacts on global temperature.

Some would call this arse-backwards when many years of scientific observations and modelling have led the world's climate scientists to exactly the opposite conclusion. But as we all know the entire scientific community has been captured by an unthinking infatuation with Al Gore who invented the idea of climate change (along with the internet) while conspiring at the UN to institute a world socialist government back in the Clinton Administration.

Seriously, this clause is much better than the original one in the confidence and supply agreement. It should be possible to get reputable scientists and economists to greatly enlighten the committee about the observations and projections that form the basis of international concern on this issue. It is also true that there are uncertainties and risks in our current knowledge. Many of these are on the "down-side" as John Key would say.

The previous demand for opposing views on the science was merely an invitation for poorly credentialed cranks to waste the select committee's time.

Great News on Climate Change and Energy

President-Elect Obama is set to appoint Nobel Prize winning physicist Secretary of Energy.

For those of us in the science community wondering how to communicate the urgency of the situation to politicians and the wider community this seems to indicate that scientists who dedicate themselves to working on this issue can have an impact.

I hope it is also a sign that the Obama administration will be able to make some progress, despite the global financial and economic crisis.

Chu used to work in my field of atomic, molecular and optical physics before shifting to the top job at Lawrence Berkeley Labs to work on alternative energy sources several years ago. Some of Professor Chu's thoughts on climate change can be found here.

ACT in Government: Wasting your taxpayer dollar

Lets be clear. The Select Committee review of emmissions trading is a waste of money and a broken election promise on the part of National.

National was quite emphatic before the election that the ETS would not be repealed, that emissions trading would go ahead, and certainly that "the scientific aspects of climate change" were no longer up for discussion by New Zealand politicians.

We appear to be back to square one, at least if the select committee Terms of Reference in the confidence and supply agreement are final, or if Murial Newman gets her way. Here she is in the NBR spouting the "warming stopped in '98" canard and calling for a select committee review "of the science". As if scientists were not continually engaged in reviewing the scientific aspects of climate change!

It's breathtaking that ACT want to hear "competing views on the scientific aspects of climate change from internationally respected sources" when pretty much every scientific association in the world, including our own Royal Society of New Zealand, has carried out a careful review of the science and concluded that anthropogenic global warming is real.

I challenge ACT to find an internationally respected source to disagree. (And no, Thatcher-era UK cabinet ministers don't count. I'm interested in a scientifically respected source.)

In any case everyone is in agreement on this point so write a letter to John Key already.

Shock: Global Warming Still Happening!

Poneke is the local advocate for the view that global warming stopped in 1998. This canard is related to the fact that 1998 was just a shockingly hot year, the hottest on record.

It is true that warming in the last decade is slower than in the previous
decade due to a dramatic El Nino event in 1998 and La Nina conditions in the last twelve months or so.

However if you get the global average temperature data and fit a line to the last ten years then sure enough it has a positive gradient indicating a warming trend. For what that is worth on such a short timescale.

There is as yet no evidence that the underlying warming trend in global average temperatures has changed.

The Met Office in the UK has just released a press release to go along with this plot of their latest data (their methodology for this data is indeed described in a 2006 peer reviewed article.). (Hat-tip Climate Progress)

Anyone who thinks global warming has stopped has their head in the sand. The evidence is clear – the long-term trend in global temperatures is rising, and humans are largely responsible for this rise. Global warming does not mean that each year will be warmer than the last, natural phenomena will mean that some years will be much warmer and others cooler.

But once again a picture is worth a thousand words. Here is a plot of global average temperatures (relative the the average temperature during 1961-1990) for the last thirty years or so.



It's really the thirty year trend that you should pay attention to, that is about the shortest period you should be looking at to determine long term trends related to climate rather than weather.

In their discussion of the current La Nina related "low" temperatures, they note

despite this temporary cooling, 2008 is still likely to be the seventh warmest on the global record.

As a result of such fluctuations, global average temperature trends calculated over ten-year periods have varied since the mid-1970s, from a modest cooling to a warming rate of more than 0.3 °C per decade. Similar behaviour is also seen in individual model predictions of future climate change where the long-term warming trend is forecast to exceed 2 °C per century. Even then, due to the natural variations in climate, we expect to see ten-year periods both globally and regionally with little or no warming and other ten-year periods with very rapid warming. This complex behaviour of the climate system shows why we need to examine much longer periods than ten years if we are to fully understand and quantify how the climate is changing.

Science journalism and the methane "time bomb"

It must really suck to be a science journalist at a high profile international newspaper. It's a genuinely difficult area to get up to speed on but unlike your colleagues covering Britney Spears you have essentially no chance of getting a scoop.

All the big science news and quite a lot of not very big news gets published in the refereed journals Science and Nature. But both of those journals prepare their own media materials and strictly embargo articles published in them. These embargoes are very tightly enforced by the journals, sometimes even to the extent of sending staff to scientific conferences to check that the authors do not spill the beans in advance of publication. Every week you can find out what's big in Science or Nature by reading the press release regurgitated in the NYT or on CNN's web page.

If you want to make a splash as a science journalist though you should get some hapless fool of a scientist to talk to you about their recent work prior to acceptance, prior even to writing a scientific paper. As No Right Turn and Hot Topic have noted, Steve Connor at the Independent has recently pulled this wheeze. (Note the proud billing "exclusive") We are told that frightening amounts methane are being emitted from ground exposed by thawing permafrost.

Unfortunately it is totally impossible to assess the merits of this research without a scientific article. What I can guarantee is that Orjan Gustafsson's scientific colleagues are spitting tacks at this display of science by press release. And yes, we learn that the enterprising science writer at the Guardian has already found one of them to describe Gustafsson's work as "speculation". The wonders of journalistic competition!

These kinds of articles are part of the problem not part of the solution. Science journalists could make themselves more useful but reporting on the settled scientific knowledge about our changing climate and thinking seriously about difficult issues like "false balance" in their reporting.

Arctic Sea Ice

This year Arctic sea ice has contracted to essentially the same level as last year's dramatic and poorly understood record low. Read about it at Dot Earth but sometimes a picture is worth a thousand words:



This picture of the area of floating ice is stolen from the Dot Earth blog and was prepared by William Chapman at the University of Illinois.

Now Poneke describes this as "good news". Call me a pessimist but that may be overstating the case.

Adding Noughts on Climate Change

When I started writing this blog I thought that I would talk quite a bit about climate change and climate change policy. Partly I was struck at Christmas time when my cousin, who works for a bank in a fairly senior capacity, announced that climate change was just a fraud perpetrated by politicians. Perhaps he was even serious but I was too stunned, and indeed ill-informed, to pursue the topic! In any case, I had the impression that the disparagement of the scientific consensus that human activities are heating the earth, particularly by those on the right of politics, was proving more stubborn in New Zealand than in the US for example. The emissions trading legislation was shaping up as one of the big issues of the year.

I haven't really said much for several reasons. Firstly I don't know enough about economics to get down in the dirty details of emissions trading schemes and carbon taxes. Secondly I am not a climate scientist so I don't have a lot to say about the detailed science. If you want to hear about climate change from climate change scientists read Real Climate and the refereed scientific literature. Thirdly embarking on this issue seems to be a great way to attract cranks and trolls. There is often a tone of barely controlled hysteria on both sides.

So all in all it often seems that there are too many challenges in attempting to communicate effectively on the subject. Instead I've hatched a plan to run a course on the physics of climate and energy. This is probably a better use of my time, and provides an excuse to learn more about the details of the science.

However the Kiwi blogosphere has been replete with discussions of this issue and at some point I just want to get stuck in. I've been trying and failing to write the one perfect blog post about the physics of climate change but I am going to leave that for now and just get stuck in on some recent issues in true reactive blog style.

So henceforth I will be joining the "climate change jihad".

Royal Society of New Zealand on Climate Change

Comments here. Hat-tip: No Right Turn.

Draft of Garnaut Report on Climate Change Out

You can find a copy on the Australian's web page. Look out for coverage over the next couple of days. (But don't expect much discussion of the New Zealand proposals, we just don't rate the kind of attention over there that many seem to hope for.)

In recent weeks Rudd, Swann, Wong and others have been walking back the suggestion (based on election campaigning) that they will follow whatever advice is contained in it. Rudd is now saying the report is "just one input" into eventual policy. A government green paper will be released by Wong July 16.

When did we stop thinking about carbon taxes?

I am very much a late-comer to the big questions of climate change policy. But there seems to have been a very broad consensus for some time now in Australia and New Zealand to back Emissions Trading Schemes of some kind, with both main parties in both countries being in favour.

Now in the Kyoto environment with definite emissions targets this seems like a good way to guarantee specific emissions levels. There are also good examples of working markets like the SO2 market in the US. In fact, I believe that as residents of Los Angeles for nearly four years my lungs are beneficiaries of some of the earliest emissions trading markets, aiming to reduce the notorious smog there. On the other hand the possibilities for rorting and gaming such systems seem to have had a very negative effect on the European CO2 market, and the politics in Australia and New Zealand begin to make it look like getting a scheme with teeth is too hard even with in principle support from essentially everyone.

It's interesting that in the US there is still a lively debate on the question of whether "cap-and-trade" (Yankee for ETS) or carbon taxes are the way to go. (There is a cap-and-trade bill in the Senate at the moment though.) I found this article to be a very interesting background to this debate. (Hat-tip Andrew Sullivan).

One person quoted there is William Nordhaus, one of the main exponents of a carbon tax, who has just written a fascinating sounding book that is reviewed here by the theoretical physicist Freeman Dyson. (Hat-tip Michael Nielsen)

Why is it not much simpler to just tax greenhouse gas emissions in terms of equivalent tonnes of CO2? (Or preferably commodities like petrol whose use will result in greenhouse gas emissions). One then adjusts the tax level, either to achieve the desired reduction in emissions or as we learn more about the response of the climate to our dangerous experiment of doubling atmospheric CO2 levels. In New Zealand this would absolutely have to include a tax on cattle, which I seem to recall has been pretty unpopular, but that should keep the Greens happy! If things are structured so as not to enormously increase Government revenue Tories might not be so put out either.

I'm now going to try to find out why this has not been the preferred option in the Antipodes.