Source: BBC Radio 4
URL: N/A
Date: 15/02/2019
Event: More or Less: Climate Change
Credit: BBC Radio 4
People:
Tim Harford: But first - on Tuesday, Today programme listeners woke up to the news that the left-leaning think tank the Institute for Public Policy Research had new statistics that showed the scale of the damage we humans are doing to the planet.
Martha Kearney: ... when you look at the scale of the problems outlined in the report, like the number of floods increasing by 15 times since 2005, extinction rates increasing by a huge rate - are these reversible?
Tim Harford: The same numbers were reported in the Guardian and elsewhere but they just didn't sound quite right to some people, for example Mark Lynas, author of Six Degrees, a book about the effects of climate change.
Mark Lynas: So this jumped out at me, because I was just in the middle of doing some research about the impacts of climate change for a book I'm updating, and it struck me that the claim that was being made about floods increasing by 15 times in the last few years since 2005, and it just just did not ring true to what I understood about the science, so far.
Tim Harford: So what happened next?
Mark Lynas: This is one of those rare instances where Twitter actually leads to a positive engagement and a friendly result on a debate about something, in that I tweeted that this didn't sound right to me and one of the authors of the IPPR report responded and said actually it was a typo and where they'd put "since 2005" that should have been "since 1950" that these increases and climate damages had supposedly happened.
Tim Harford: I'm not sure that's really how typos work - maybe we should say that was a mistake rather than a typo. But anyway, fine...
Mark Lynas: Yes, [laughs] and also I still wasn't quite satisfied with that, either, so it didn't still didn't sound right, because if you look at the IPCC, which is the Intergovernmental Panel on Climate Change, where all of the scientific consensus material is written in these weighty reports every few years, they say they are not confident that there's been any increase in flooding around the world. So heavy rainfall has got worse, yes there's been an increase in heat waves but nothing like the magnitude of what was being claimed in the IPPR report. And I wanted to know the source, and they said that the research came from Jeremy Grantham, who's a rich person who writes reports on environmental things and his source supposedly was a database of emergencies and disasters and then, Twitter being amazing, the administrator of the database then got onto this and said that they didn't think it was correct for their database to be used to claim trends in numbers of floods.
Tim Harford: Why not? I mean, it sounds like a reasonable source.
Mark Lynas: It does, but the thing is - there's lots of other things that affect floods' impacts other than just climate change, for example what's happening in the built environment, more structures there which are likely to get flooded, so economic growth and population changes can have a - well, do have a much, much bigger impact on recorded damages than just climate trends.
Tim Harford: Okay, so the source of the claim was a database and the administrator of the database says you shouldn't use our database to draw conclusions about the impact of climate change. So what do we know? I mean, you've written about this - what do we know about the impacts of climate change on extreme weather, flooding and so on?
Mark Lynas: We actually know quite a lot. The IPPR had said that floods have increased 15 times since 2005 - or corrected to 1950 - but if you do look at what the scientists are saying, so look at the Intergovernmental Panel on Climate Change, the IPCC, and - if I quote you from their latest report which was issued only a few months ago, they say: in summary, extreme flow trends since 1950 are not statistically significant in most of the world's largest rivers, while flood frequency and extreme stream flow have increased in some regions. So it's very different from what the IPPR were claiming, and - you know I am not a climate sceptic, I'm not somebody who goes out there trying to debunk what's being said about the urgency of climate change, but if you overstate the case and you use erroneous facts and figures, then I think you undermine a lot of what was in the report, which I thought was actually very valuable.
Tim Harford: Mark Lynas.