Earth's next ice age could be delayed by global warming, research finds

Does it feel hot in here? Well, it may do for some time, with scientists predicting that the next ice age could be delayed. What’s more, carbon dioxide emissions may have something to do with it.  The current warm interglacial period could continue for longer than expected – with some climate models even suggesting another 500,000 years – if we consume all the fossil fuel reserves, according to scientists at University College London and Cambridge University.

‘There have been lots of climate models published that say if we stopped pumping carbon dioxide into the atmosphere today, we would probably remain in an interglacial state for the next 50,000 years,’ said lead author Prof Chronis Tzedakis, from UCL.  ‘One, because the summer solar radiation changes are subdued during this period and two, because the CO2 concentrations are so high it just won’t get cold enough.’

The research, which was conducted by comparing the current climate with a similar period 780,000 years ago, revealed that CO2 levels – which are currently about 380 parts per million – would need to fall to about 240ppm in order to glaciate.  ‘Although some people are rejoicing that we have “avoided” an imminent glaciation, the real message here is that the climate system may be highly sensitive to small changes in CO2,’ said Dr Luke Skinner, from Cambridge University

‘We could say that if we were trying to avoid a glaciation by emitting CO2, we have tried too hard.’  Prof Tzedakis added: ‘If we stopped pumping CO2 today, it would take a very long time for it to be completely removed from the atmosphere through natural processes.’  With pre-industrial CO2 concentrations of 280ppm sufficient enough to delay the ice age therefore, there seems to be little to support the impact of human emissions on this.

Some scientists argue that atmospheric CO2 would naturally have been at about 240ppm today if early humans had not already caused gases to start rising gently from 8,000 years ago in the early farming practices.  ‘Regardless of whether or not this is true, a change of 40ppm seems to have been enough to change the course of climate history for quite some time, which puts into perspective the massive 100ppm change that we have effected since the industrial revolution,’ he said.

‘Arguably, any change in our future emissions will result in a different future climate outcome. What is especially difficult though is to know in advance what level of sacrifice is required or warranted for a given “target” climate outcome.  Prof Tzedakis said: ‘The main fundamental question underlying all this is, at what level do we reach dangerous climate change? There is a big debate about this, with some scientists saying we have already reached it.

‘The rate of increase is relentless and it is a huge challenge to slow it down. There isn’t going to be one or two solutions. It is about dividing the problem and everyone trying to do something.’ One possible solution is carbon capture, where  CO2 is scrubbed from the air.  Although this is yet to be rolled out on a large scale, research suggests that a new polymeric material may be used to capture carbon dioxide at the source – such as a car’s exhaust pipe.

‘Taking CO2 directly out of the atmosphere must be the holy grail of climate change mitigation,’ said Dr Skinner.  ‘Can it be done on a large scale? I suspect that “hoping so” will not be enough… but let’s hope so nonetheless.’

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