Climate Change

The Intergovernmental Panel on Climate Change (IPCC)’s Fifth Assessment Report (AR5) is available here.
Richard Tol’s critique published in the Financial Times is available here.

22 replies on “Climate Change”

So, according to this, Tol’s source for the 0.2-2 percent of GDP is . . . wait for it . . . Richard Tol. He put it in the IPCC draft summary and, when the final summary expressed “less certainty” about the impact, he took his name off it.

Still, good to see the old boy still milking the same trick: by being “out on the fringe” (the Economic equivalent of Robert Faurisson in History) he gets to increase his citation count as every non-fringe scientist feels obliged to take a shot at him. Then he gets to trumpet how he’s “the most widely cited economist” working in wherever he’s working. That he’s cited for being wrong is apparently of no consequence.

All of the points in his article are sensible. Warlords and rubbish roads, poor land tenure, and weak governments are all real problems, and symptoms of underdevelopment.
The question he ducks is what will climate change do to all of these problems? If the experience of the Horn of Africa is any guide, climate change, even very modest change, will likely make all of these worse.
Dealing with underdevelopment and dealing with climate change are not antagonistic positions, but we likely need to do both, and do both quickly.

It’s not ad hominem to point out:

1) Tol’s source for his figures is his own, disputed, contribution to the IPCC report;
2) He has been described (euphemistically) as not within the mainstream consensus on these matters;
3) He is widely cited because most everyone disagrees with him and there aren’t very many at all on his side;
4) He constantly trumpets how frequently cited he is as if that alone meant that he was doing important work.

I’m sure he’s a fine fellow, however.


“That he’s cited for being wrong is apparently of no consequence.

Merely a particular instance of the general w.r.t. economists.

The species damage to the ecosphere reminds me a detailed, comprehensive, one word report that Seven_of_9 replied in response to a request from the Federation Council on a query re the relevance of the word ‘sapiens’ as applied to humans:


@Richard Tol

“Climate change is complex and its impacts more so. We have limited knowledge of the consequences of the modest change that has occurred in the past. There is even more uncertainty about the effects of the rapid change expected in the future.”

You present a reasonably plausible alternative perspective, focused on possible and probably necessary adaptations to climate change, that has merit.

I suspect that this ‘take’ will be mis-appropriately morphed by the PR brigade of the Frack_Europe Vultures into something far less benign.

p.s. neat win vs England in Bangladesh today. Orangemen!



Speaking after a meeting with European leaders at the EU-US summit in Brussels on Wednesday, President Barack Obama suggested that the U.S. is open to exporting fracked shale gas, once promised as the source of American “energy independence,” to the EU and urged the EU to open up its own fracking reserves amid energy fears related to the crisis in Ukraine. Environmental groups have warned these policies will do nothing by way of energy security and everything for global environmental destruction and climate chaos.

“Once we have a trade agreement in place,” Obama said at a news conference in Brussels in reference to the Transatlantic Trade and Investment Partnership deal currently in the works, “export licenses for projects for liquefied natural gas destined to Europe would be much easier, something that is obviously relevant in today’s geopolitical environment.” [H/T

Tol’s article blithely dismisses the impact of global warming by highlighting how it can be mitigated by (enormous) investment – you know rebuild Thames barrier etc.
Things that rich nations can do
As for the bottom billion well they don’t really feature at all

As Tom Lehrer sang “that’s not my department said Werner Von Braun”

“Global Warming!!!” Is this some distraction? What’s happening that we need to be ‘entertained’?

How about the deterioration in the global environment – atmospheric, land and water pollution? That’s probably a more immediate problem. But mankind has been there before and just ignored it. Same now. Same outcome.

Economically mitigate those negative externalities? Localized local efforts sure, but that will be the limit. Too costly. Follow the votes!

And as for the almost ultimate in obscene political propaganda:-

” … export licenses for projects for liquefied natural gas destined to Europe would be much easier …”

Liquified NG is deeply frozen and highly compressed (to keep it liquid). Export licenses are pieces of paper – but the infrastructure to liquify, transport and re-gasify NG will prove to be a cost to far. It easier, and more profitable, to emit virtual credit and churn financial products. More fun too.

Now if our great scientists, engineers, mathematicians and economists would like to provide a fair and true analysis of the research works of M King Hubbard and Albert Bartlett. At least there is a sufficient amount of statistically reliable empirical evidence to support their theories. Very inconvenient – politically.

Positive Money in the UK provide a good analysis of how our current debt-based, perpetual-expansion monetary system leads to environmental damage. To summarise:

1. The system breaks down periodically and governments and people ‘forget’ about the environment when dealing with a financial crisis.

2. The system is only fit for purpose when it’s expanding. This need not be the case if, for example, central banks had the power to create money and it wasn’t routinely destroyed through loan repayments.

3. Countries are artificially incentivised to become net exporters adding pressure to produce more and sell it further away.

For more information on each of the above and how we could transition to a more steady state economy visit;

“Climate change is complex and its impacts more so. We have limited knowledge of the consequences of the modest change that has occurred in the past. There is even more uncertainty about the effects of the rapid change expected in the future.”

So we shouldn’t do anything.

I’d take Feyman over Tol every time

“Some years ago I had a conversation with a layman about flying saucers…. I said, “I don’t think there are flying saucers.” So my antagonist said, “Is it impossible that there are flying saucers? Can you prove that it’s impossible?”
“No,” I said, “I can’t prove it’s impossible. It’s just very unlikely.” At that he said, “You are very unscientific. If you can’t prove it impossible, then how can you say that it’s unlikely?” But that is the way that is scientific. It is scientific only to say what is more likely and what less likely, and not to be proving all the time the possible and impossible.”

“A deeper problem, however, is that there’s no new normal to aim for, no way to reestablish the textbook formulas that served us well. We’ve increased the temperature one degree so far, but the same climatologists who predicted that rise also tell us that unless we can quickly break our addiction to fossil fuels, we can anticipate four or five degrees as the century wears on. Each increment adds new energy to the system, and at the upper boundaries engineering as we’ve known it becomes very nearly impossible”

@ Ernie

how did he calculate that 2%? do you think his model included the likelihood for the Gulf Stream collapsing or of world food production falling by 20% ?


reading papers from William Nordhaus, the Nicolas Stern report, (Nordhaus critizing Stern for a too low discount rate, somewhere 2012), Samuel Fankhauser “Valuing Climate Change” give similar considerations, over where the optimum of short term efforts for CO2 output reduction should be.

On a local note, I can say since this weekend, that with a probability of > 99.5% it was the burning of dirty homegrown lignite without proper filters, which kept the Elbe floods away for 60 years, happening every 12 years before and after.

Now, what are we going to do about that? Remove the filters, burn a lot more home grown lignite, increasing our energy independence,

people will get used again to a little constant coughing, or …… ?

The IPCC ‘Summary for Policy Makers’ includes the following
‘Global economic impacts from climate change are difficult to estimate. Economic impact estimates completed over the past 20 years vary in their coverage of subsets of economic sectors and depend on a large number of assumptions, many of which are disputable, and many
estimates do not account for catastrophic changes, tipping points, and many other factors. With these recognized limitations, the incomplete estimates of global annual economic losses for additional temperature increases of ~2°C are between 0.2 and 2.0% of income (±1 standard deviation around the mean) (medium evidence, medium agreement). Losses are more likely than not to be greater, rather than smaller, than this range (limited evidence, high agreement).Additionally, there are large differences between and within countries. Losses accelerate with greater warming (limited evidence, high agreement), but few quantitative estimates have been completed for additional warming around 3°C or above.

In general, it is striking to compare the actual text with the media coverage. The latter don’t do uncertainty or probability while the IPCC includes qualifiers in relation to the main findings, as illustrated above, citing the extent of evidence in support and the level of expert agreement.

@ Dan McLaughlin

“while the IPCC includes qualifiers in relation to the main findings, as illustrated above, citing the extent of evidence in support and the level of expert agreement.”

There is no “evidence” to cover what happens if global average temperatures increase by 2 degrees. Bloomberg don’t have anything. It is uncharted territory. Economists can’t even credibly project economic growth 5 years from now so how Tol derived 2% of GDP deserves to be promoted to a mystery of the Rosary.


And there’s another citation for Richard Tol, the “Scholar most-cited by the Stern Review of the Economics of Climate Change”! Congratulations, Richard!

From Prof Cameron Hepburn.

Sir, Richard Tol makes the valid point that action on climate change should be coolly compared with other investments (“Bogus prophecies of doom will not fix the climate”, April 1).

But his conclusions rest upon dangerously incomplete economic models that ignore critical risks and the failure to recognise that business as usual is taking us towards global warming of 4C, not 2C.
He cites figures, based on his own work, from the new report of the Intergovernmental Panel on Climate Change which suggests that further global warming of 2C could cause losses equivalent to between 0.2 and 2.0 per cent of global income.

But the IPCC itself has warned that these numbers omit many of the impacts of climate change, including potentially catastrophic risks such as the irreversible melting of the Greenland ice sheet and resultant sea level rise. These are risks that would undermine economic growth and development across the world.
Prof Tol is on firm ground with his conclusion that “we had better start now”. Climate scientists have shown current trends in annual global emissions of greenhouse gases to be more consistent with warming of 4C than 2C, which would create much higher risks of catastrophic impacts.
Although a 4C increase is not yet unavoidable, there are massive lags created by the lock-in of high-carbon energy infrastructure and the relatively slow response of the Earth’s climatic system to rapidly rising levels of greenhouse gases in the atmosphere. Accelerated cuts in emissions are required to avoid the biggest risks.
The economically rational prescriptions are a strong carbon price, support for R&D to reduce costs of cleaner technologies, and measures to address related market failures.
Prof Tol’s article unfortunately demonstrates that economic analysis based on incomplete models can lead to pronouncements about the risks of climate change that are at best complacent, and at worst reckless.

Cameron Hepburn, Professor of Environmental Economics, University of Oxford, UK

From Dr Gernot Wagner and Prof Martin L Weitzman.

Sir, Richard Tol asserts that “Bogus prophecies of doom will not fix the climate” (Comment, 1 April). He’s right to highlight the importance of adaptation measures to deal with the worst, but he’s wrong in presenting climate change as a problem with seemingly certain temperature outcomes.

It’s not the near-certain warming of 2C that should worry us the most, though that might be damaging enough. The core problem is that we are deeply unsure of the relationship between high greenhouse gas concentrations and eventual high temperature changes like 4C or 6C (or possibly higher). And we are even more unsure about the relationship between high temperature changes and future climate-change damages, or how to discount these future damages into today’s values.

Climate change, in the end, is a risk management problem. A lot of it has to do with buying insurance against worst-case outcomes. Far from declaring the notion of existential risk “laughable,” as Dr Tol does, we should focus seriously on these high-impact events to help drive our decisions around pricing carbon today. And price carbon we must.

Gernot Wagner, Senior Economist, Environmental Defense Fund

Martin L Weitzman, Professor of Economics, Harvard University, Cambridge, MA, US

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