The BBC just can’t seem to stop itself trying to frighten people over climate change. On Tuesday morning it was the turn of Radio 4’s Food for Life by King’s College London professor Tim Spector. The show began with an extraordinary claim: ‘Most predictions concur that if we don’t change our habits fast, by 2050 the Earth will have lost most of its trees and habitable areas.’
Really? I contacted Spector over where he sourced this claim and was told that the claims were ‘in the IPCC reports’. But are we really on course to lose most of our trees in just 26 years’ time? The IPCC’s latest Special Report on Climate Change and Land does not appear to make any confident prediction for future tree cover, and there is not a lot of support for Spector’s claim from data from the UN Food and Agriculture Organisation. There has been a substantial net loss of global forest area in recent years: 4.7 million hectares per year between 2010 and 2020. But to put that into context there is still an estimated four billion hectares of forest. The net loss in the 2010s, in other words, represents less than 1.2 per cent of the total. Moreover, the rate of deforestation has been gradually falling in recent decades – it was 78 million hectares in the 1990s and 52 million hectares in the 2000s.
In other words if we carry on the way we are going we might expect to lose no more than around 3 per cent of our forest over the next three decades – which is hardly ‘most’ of our trees.
As for the claim that we will lose most of our habitable areas, it is hard to know what is meant by this. Did Spector mean wide areas are going to be flooded? The IPCC suggests global sea levels will rise by between 0.15 and 0.29 metres by 2050. That might nibble away at some coastal areas but will hardly reduce habitable areas by half.
Did he mean places would become scorched, or too hot for habitation? Even in the very worst-case modelled scenario presented by the IPCC global temperatures would rise by a further 1.3 Celsius by mid-century. It hardly seems remotely plausible that over half the inhabited area of the Earth is going to become too hot for habitation, even at that level.
Or did he mean that half the Earth’s agricultural land will become degraded? That is hardly borne out by the data presented in the latest IPCC report, which quotes a number of studies on land condition.
One suggests that between 22 and 24 per cent of global ice-free land is currently in a declining physical condition and 16 per cent is improving; another claimed that between 1999 and 2013, 20 per cent of land declined in condition and 20 per cent improved. Just because land is declining in condition, by the way, doesn’t mean it is going to become uninhabitable or unavailable for cultivation – it just means it is declining to some extent. The IPCC Special Report on Climate Change and Land doesn’t try to quantify possible loss of habitable land, but it does come up with a scenario in which land which is home to 178 million people becomes ‘vulnerable to water stress, drought intensity and habitat degradation’ if temperatures are 1.5 C above pre-industrial levels by 2050 and 277 million if they are 3 C above pre-industrial levels. The latter figure is equivalent to 3.4 per cent of the current global population.
In short, there is nothing remotely to back the professor’s assertion – it is the sort of hyperbole which you might think the BBC had by now become wise to.
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