Guest essay by Eric Worrall

An almost balanced description of lukewarmer views; I had to check twice to verify this story was actually published on the Aussie ABC website.

Are economists globally understating or overstating the cost of climate change? 

By business reporter Nassim Khadem

In a blog written after the devastating bushfires that swept across his home state of New South Wales, Australian economist Steve Keen states, “I have to admit that I am personally not coping well with climate change”.

Professor Keen says he’s feeling the “same generalised anxiety about the future felt by Greta Thunberg and the young people she’s inspired to strike for the climate”, before criticising the work of William Nordhaus and other neoclassical economists.

“Since policymakers take what economists predict seriously — even after the 2008 financial crisis — they have been duped and have drastically underestimated how severe climate change will actually be,” Professor Keen argues.

William Nordhaus is a renowned American economist whose work modelling the economic impact of climate change earned him the 2018 Nobel Memorial Prize in Economic Sciences.

He is not a climate change denialist. His view is that greenhouse gas emissions from human activities will have a negative impact and he’s urged governments globally to implement a carbon tax.

But it’s the extent to which Professor Nordhaus — and other economists who agree with him — predict climate change will impact the economy (and thereby the level of action needed to curb it) that has been the subject of intense debate.

The Paris Agreement goal is to keep global warming this century well below two degrees Celsius compared with pre-industrial levels.

At one end of the scale are Professor Nordhaus and Richard Tol.

Tol, a professor of economics at the University of Sussex, has since 1994 been a convening lead author with the United Nations body for assessing the science related to climate change, the Intergovernmental Panel on Climate Change (IPCC).

Both Nordhaus and Tol argue that the world can survive a 4°C increase in global average temperature and the economic impact won’t be severe.

They also argue we shouldn’t reduce emissions too quickly, because the economic cost to people today will be higher than the benefit of protecting people in the future.

Professor Nordhaus told ABC News he was not available to comment, but has previously said that “optimal policy” would result in global warming of about 3°C by 2100 and 4°C by 2150.

…

Read more: https://www.abc.net.au/news/2020-02-06/are-economists-understating-or-overstating-climate-change-cost/11929098

The article also provides a lot of space to arguments that optimistic viewpoints don’t account for predicted tipping points. But, well this is the Aussie ABC – they normally don’t bother presenting both sides of climate arguments.

What about the points raised in the article? I think the short summary is, without tipping points they’ve got nothing. A few degrees warming is like moving a few hundred miles closer to the equator – utterly inconsequential.

How consequential are predictions of dangerous tipping points? The problem with tipping points is they break the math, like a bad infinity inserted into an equation. If you postulate “at this point we all suddenly die”, you can justify anything, no matter how improbable, because the death of the entire world is something to be avoided at all costs.

Except you can’t live this way. There is a huge range of improbable but high impact events which could claim our attention, ranging from lethal global pandemics, extinction level asteroid strikes, nuclear war, an endless list of unlikely ways we might all meet our end. We have nowhere near the resources required to address them all.

And at least one of those events, the risk of a world ending lethal global pandemic, seems a little more real right now than the remote possibility a handful of scary but unverifiable climate model artefacts might actually be an accurate reflection of future reality.