Climate records are being smashed, and not in a good way. In July last year I wrote about how 2015 was set to become the first year with an average global surface temperature more than 1 °C higher than before the rise of modern industry.
And the warming did not stop in 2015. Surface temperatures are now shooting up at the fastest rates ever recorded. Contrary to what some reports implied, we are nowhere near to the – somewhat arbitrary – 2 °C mark regarded as a dangerous level of warming, but we are whizzing past the halfway point at a dizzying rate.
But it’s not just surface temperatures that are soaring. This week I reported that carbon dioxide levels in the atmosphere are rising at the fastest rates ever recorded – and thanks to ice cores our records go back 800,000 years.
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These are alarming figures, but what we are seeing are short-term spikes linked to the ongoing El Niño. It’s the long-term trends we need to stay focused on – and they are far more frightening.
Temperature spike
Let’s start with the temperature spike. The Earth as a whole has not suddenly started retaining more heat. Instead the oceans – which soak up more than 90 per cent of the extra heat created by global warming – have been absorbing slightly less than usual, thanks to El Niño. This has resulted in a rapid rise in surface temperatures.
If the current El Niño is followed by a La Niña later this year, the oceans will soak up even more heat than usual and surface temperatures will fall (even though the planet as a whole is still warming). So while 2016 is likely to be the warmest year on record, at about 1.1 °C above preindustrial levels, 2017 and 2018 will probably be cooler.
Ultimately, though, how fast the world warms depends on the level of CO2 in the atmosphere. Here the record rise of over 3 parts per million seen in 2015 is part of a long-term trend: the amount of CO2 added to the atmosphere each year is growing, from an average of under 1 ppm per year in the 1960s to over 2 ppm a year in the past decade.
Rising CO2, falling emissions?
This means in the not too distant future, surface temperatures will rise consistently above the record-breaking levels we are now seeing. What’s more, CO2 is still being released into the atmosphere at faster and faster rates, Ralph Keeling of the Scripps Institution of Oceanography, who monitors CO2 levels, told me this week.
That may come as a surprise if you have been reading about the rise of renewables and the death of coal, and how global CO2 emissions actually fell in 2015. How can CO2 levels still be rising ever faster if emissions are falling?
There’s no doubt that the 3 ppm spike has a lot to do with El Niño – the drought conditions El Niños create in many regions slow plant growth and increase wildfires, meaning more CO2 in the atmosphere. And the current spike might so large that it is masking a small recent fall in emissions due to human activity.
Questionable figures
I’d love to believe this. But the studies suggesting there has been a fall in emissions looked only at emissions from energy generation and industry. They do not include emissions from changes in land use, such as deforestation and the loss of peat. If land usage is included, it is likely that human emissions are still increasing overall, one of the authors of those studies, Corinne Le Quéré of the University of East Anglia, told me last year.
What’s more, such studies have to rely largely on countries’ own estimates of their emissions – and it’s not just China’s figures that are questionable. The European Union, for instance, does not count emissions from the – but wood-pellet burning can emit even more CO2 than coal burning.
The level of CO2 in the atmosphere is the single most important measure of global warming, because it determines how much hotter the planet will become. As long as it continues to increase ever faster, claims that we are making progress in our efforts to limit future warming should be taken with a big pinch of salt.
