Source: BBC
Human societies will soon start to experience adverse effects from manmade climate change, a prominent economist has warned.
Prof Richard Tol predicts the downsides of warming will outweigh the advantages with a global warming of 1.1C – which has nearly been reached already.
Prof Tol is regarded by many campaigners as a climate “sceptic”.
He has previously highlighted the positive effects of CO2 in fertilising crops and forests.
His work is widely cited by climate contrarians.
“Most people would argue that slight warming is probably beneficial for human welfare on net, if you measure it in dollars, but more pronounced warming is probably a net negative,” Prof Tol told the BBC Radio 4 series Changing Climate.
Asked whether societies were at the point where the benefits start to be outweighed by consequences, he replied: “Yes. In academic circles, this is actually an uncontroversial finding.”
But it is controversial for climate contrarians, who often cite Professor Tol’s work to suggest that we shouldn’t worry about warming.
Managing ecosystems
Matt Ridley, the influential Conservative science writer, said he believed the world would probably benefit from a temperature rise of up to 2C.
“I think we probably will see 1.5 degrees of warming. The point is most people think 2C is when it turns catastrophic. That’s not right. The literature is very clear; 2C is when we start to get harm. Up until then we get benefit,” he said.
“We’ve got a greening in all ecosystems as a result of CO2. We’ve got about 11% more green vegetation on the planet than 30 years ago, much of which is down to the CO2 fertilisation effect.”
On fertilisation Matt Ridley refers to unpublished work by Professor Ranga Myneni from Boston University.
But he told BBC News Lord Ridley had accurately quoted his research on the impacts of current CO2 levels, but was unduly complacent about future warming.
“I am worried about how this work is being interpreted, by Lord Ridley. In my opinion, [CO2 fertilisation] benefit of greening is not worth the price of all the negative changes,” he said.
Richard Tol from Sussex University believes discussion over the impacts of a 2C temperature rise is largely irrelevant as the world is likely to warm by between 3-5C, because politicians at the forthcoming Paris climate summit won’t be willing or able to make the scale of cuts needed to keep temperature rises under 2C.
Categories: Environment