Faster warming in the Arctic will be responsible for a global 2C temperature rise being reached eight years earlier than if the region was warming at the average global rate, according to a new modelling study led by UCL researchers.
The Arctic is currently warming nearly four times faster than the global average rate. The new study, published in the journal Earth System Dynamics, aimed to estimate the impact of this faster warming on how quickly the global temperature thresholds of 1.5C and 2C, set down in the Paris Agreement, are likely to be breached.
To do this, the research team created alternative climate change projections in which rapid Arctic warming was not occurring. They then compared temperatures in this hypothetical world with those of the “real-world” models and examined the timing with which the critical Paris Agreement thresholds of 1.5C and 2C were breached. They found that, in the models without fast Arctic warming, the thresholds were breached five and eight years later respectively, than their “real-world” projected dates of 2031 and 2051.
In addition, they looked at how removing rapid Arctic warming from the models would affect more pessimistic or optimistic scenarios. For example, in a more optimistic scenario, where emissions are cut sharply and net zero is reached shortly after 2050, Arctic amplification causes a seven-year difference in the time of passing 1.5°C.
Temperature projections for the Arctic varied more substantially between the models than for other parts of the globe, accounting for 15% of the uncertainty in projections, despite the region only making up 4% of the global surface area.
The 1.5C and 2C limits are regarded as having been breached when average global temperatures over a 20-year period are 1.5C or 2C higher than in pre-industrial times.
The goal of the Paris Agreement, an international treaty, is to keep the global average temperature to “well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C”.
The Arctic is thought to have warmed by 2.7C since the pre-industrial era, and this warming is believed to have accelerated since the start of the 21st century.
IMAGE CREDIT: (ENTER NAMES)
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