When it comes to climate change, there are many things of which we can be certain. Though until recently the popular emphasis – both in mainstream media and in politics – stressed what we don’t know, we now know enough to be very, very certain of a number of things.
Climate change is real, and it is happening right now: temperatures are rising, glaciers shrinking, and this year summer Arctic sea ice reached a new low. The examples are endless.
The UN process isn’t working. The insipidness of the treaty signed at Durban was predictable. And as evidenced by Canada’s official departure from the Kyoto treaty, signatories cannot be counted on to keep their word anyway. Even faithful adherence would amount to little: the UN Environment Programme (UNEP) reports that by 2020, even with perfect implementation of current pledges under the UNFCCC (UN Framework Convention on Climate Change), there will be a six gigatonne gap between what is required to limit global temperature rise to 2°C and actual emissions.
So, we can expect a 2°C rise in global temperatures – maybe even 4°C. But what – exactly – is going to happen? This seems to be the only question left worth asking.
Put another way: just how worried should we be? Predicting the future is never an exact science, and there will always be a certain degree of uncertainty. Some places may change little, such as desert interiors. Others will become unrecognizable – or vanish entirely, such as Alpine glaciers and small islands in the Pacific.
One region we may regard as a barometer for change is the Arctic, because it will warm more than regions at lower latitudes – the planet as a whole may warm up by 4°C, but the Poles could warm up by 12°C. The changes will obviously be more extreme.
What will this look like?
While most of us probably picture moist, foggy, tepid bogs, research indicates that large portions of the region may dry – and burn. As counterintuitive as it may seem, fires may become an important feature of the Arctic landscape.
Already there are signs that this is happening. From what we can glean from the geologic record, the Arctic tundra rarely experienced fires 100,000 years ago. But for the past century fires have sparked with increasing regularity and severity. The Anaktuvuk River fire in 2007 burned more than 1,000 square kilometres of tundra, in one flush doubling the amount of Alaskan tundra that has burned since 1950.
This could be just a prelude to things to come, says Dr Philip Higuera, Assistant Professor in the College of Natural Resources at the University of Idaho, who published new research this month in the journal Ecological Applications.‘Our work illustrates that some tundra regions can burn frequently, implying that future warming could certainly result in more frequent tundra burning,’ he explains.
Of crucial importance: fires could lead to more fires, and the Arctic itself may become a driver of climate change. In other words, an actual contributor to global warming, rather than a cooling refrigerant sitting atop the planet.
Burning on the tundra exacerbates climate change in several ways: fires release carbon that has been stored in the soil and vegetation to the atmosphere; the protective insulation above the permafrost is lost, leading to melting and drying; exposed, blackened earth absorbs more heat, leading to more warming and drying.
In a continuing cycle of positive feedback, fires could beget more fires, accelerating climate change the planet over, onwards and upwards.
But this is just one scenario – it is also possible that higher levels of carbon dioxide in the atmosphere (the raw material of photosynthesis, after all) could fertilize the growth of more trees in the region, which would soak up carbon from the atmosphere and act as a brake on climate change.
To better understand how the landscape might respond to burning, Dr Higerua and his team looked at how various parts of the Alaskan landscape reacted to fires over the past 2,000 years.
‘The bottom line in our new paper is that tundra fire regimes are more diverse than we previously understood, varying with subtle gradients in climate and vegetation, and likewise their ecological and physical consequences will likely vary widely as well,’ says Dr Higuera. ‘Tundra fire regimes are more varied than some media (and science) coverage suggests. But ultimately it’s the classic scientist line of “we need more research”.’
The picture is complicated, and nobody really knows what will happen. Dire predictions for the future, and phrases like ‘catastrophic climate change’, can seem so alarmist that they almost render us complacent – surely the truth can’t be so extreme that the Arctic itself would blaze.
But the very fact that it is a distinct possibility shows just how much our world is bound to change – in ways that few of us have ever thought possible.