When is a “climate briefing” not actually a briefing?
Perhaps when it’s only 90 seconds long and comes from a group with a history of promoting climate science denial that’s been in trouble with government charity watchdogs for pushing one-sided views?
The group in question is the London-based Global Warming Policy Foundation (GWPF), founded by Conservative Party peer Lord Nigel Lawson.
The briefing is one of the GWPF’s most recent YouTube videos – part of a series branded GWPF TV.
In the video, the group looks at a recent study published in the journal Nature Geoscience that examined how temperatures in the Southern Ocean around Antarctica are influenced by complex patterns of wind, ocean circulation and global warming.
According to the GWPF, the results of the paper “may mean that the Antarctic is less vulnerable to global warming than was previously thought” and that “computer models and estimates of sea level rise may need to be to be revised.”
Sea Level Rise
But before we look at those claims, let’s go back a bit.
There are two well-understood reasons why sea levels are going up.
Firstly, as the oceans get warmer, they take up more space, pushing sea levels upwards. Secondly, if ice that’s grounded on land melts – such as ice sheets and glaciers – then this adds to the volume of water in the ocean.
For the most part, melting sea ice doesn’t push sea levels up because it’s already in the ocean. This is a very important distinction to make, and should be a part of any “briefing” worth its ocean salt.
In the GWPF video, the narrative claims “climate campaigners have denied that Antarctic sea ice extent has been increasing and said that it is insignificant”.
But the media headlines the video uses to back up their case, don’t show any denial of the levels of sea ice in the Antarctic. Instead, they mostly relate to melting ice sheets.
So, does the Nature Geoscience study really mean, as the GWPF claims, that the Antarctic might be less vulnerable to global warming? I asked the lead author of the study, Dr Kyle Armour, to review the video.
Armour, of the University of Washington, said he liked the animation in the video that showed why parts of the Southern Ocean had been slow to warm, and that this was accurate.
But then, it all goes a bit south. “The video makes several statements that are not supported by our findings,” Armour told DeSmog by email.
For instance, they suggest that the observed increase in Antarctic sea ice extent since about 1980 is addressed by our paper but ignored by the climate science community. Instead, Antarctic sea ice expansion has been widely documented in the climate literature, but our paper does not discuss it.
So what does Armour make of the central claim in the video that “the Antarctic is less vulnerable to global warming than previously thought” and that “computer models and estimates of sea level rise may need to be revised”? Here's his response (with emphasis in bold added by DeSmog).
While it's true that the Antarctic sea ice expansion is not well reproduced by climate models, we find that the models robustly simulate far slower warming of the Southern Ocean than the Arctic Ocean over the last century – in good agreement with observations. That is, the models appear to be capturing the causes of slow Southern Ocean warming quite well. The reasons why they haven't simulated Antarctic sea ice expansion, on top of this background of slow Southern Ocean warming, is a topic of ongoing research by our group and others.
Moreover, our study did not address whether the slow warming of the Southern Ocean surface has implications for the melt of Antarctic ice sheet or sea level rise.
Armour also noted how the GWPF “seems to confuse several different points” in the video.
[The video] discusses Arctic sea ice melt alongside newspaper headlines about Antarctica. It further appears to conflate sea ice changes with changes in the Antarctic ice sheet. The vast majority of studies show that the Antarctic ice sheet has been losing mass over recent decades, contributing to global sea level rise, even as the sea ice around Antarctica has expanded.
The fact the GWPF has delivered a confused piece of climate communication that imagines results from a scientific paper that didn’t actually exist won’t surprise too many.
The GWPF goes much further, though, than downlpalying the impacts of human-casued climate change. Last year’s GWPF annual lecture was delivered by hard-line climate science denier Patrick Moore, who claims there is no evidence at all that humans are causing global warming.
Royal Society Controversy
This year’s GWPF lecture is being delivered by Matt Ridley – a member of the GWPF’s “academic advisory council”.
GWPF booked a room at the headquarters of the Royal Society for the lecture – a decision that DeSmog revealed has upset several Royal Society Fellows, who called, unsuccessfully, for the booking to be cancelled.
The Royal Society, the world’s oldest scientific academy, has the motto “Nullius in verba” which translates as “take nobody’s word for it”.
That’s generally good advice, especially if that word is about climate chnage science and it comes from the Global Warming Policy Foundation.