2016 Will Be Even Hotter Than 2015- The Hottest Year Ever

  Last year was the warmest year on record, smashing the record set in 2014 by a huge margin, several agencies have confirmed.

But it is unlikely to hold on to the record for long; this year is likely to be even warmer.

In 2015 the global average surface temperature was 0.75 °C higher than the 1960 to 1990 average according to the UK’s Met Office, smashing the record of 0.57 °C higher set in 2014.

That is a huge increase: record years are usually only marginally warmer than the previous record. And 2016 is expected to smash the record again, according to the Met Office, with the global surface temperature rising to 0.84 °C.

Global warming is, of course, the main reason why the record for the warmest year keeps being broken. Every year the planet as a whole is accumulating more heat energy as a result of rising greenhouse gas levels.

The vast majority of this heat goes into the oceans rather than the lower atmosphere. Just how much varies from year to year, largely because of the natural phenomenon known as the El Niño and La Niña cycle.

Underestimate?
During La Niñas, cold surface waters in the Pacific soak up even more heat than usual, which can cool the lower atmosphere and thus lower surface temperatures. During El Niños, warm surface waters in the Pacific release a little heat, warming the lower atmosphere.

We are currently in the middle of what is by some measures the strongest El Niño ever recorded, which is why global surface temperatures have shot up so much. Many other factors, from the solar cycle to levels of aerosol pollution in the atmosphere, also have a role.

As New Scientist revealed in July, we are already halfway to 2 °C – the level countries decided it would be dangerous to exceed.

Average global surface temperatures have now risen by more than 1 °C compared with pre-industrial times, according to all the main records of global surface temperatures, including those compiled by the UK’s Met Office, and by NASA and NOAA in the US.

These records differ slightly because of the way they handle regions where there are no weather stations, like most of the fast-warming Arctic. The Met Office record simply excludes these regions – and thus likely underestimates global warming – while the others extrapolate the missing data by various methods.

Even if countries stick to the climate change commitments they made at the UN climate summit in Paris in November last year, the world is currently on track to warm by 3 or 4 °C by 2100. That is the most likely outcome for the estimated amount of emissions, but the resulting warming could be less than this, or as much as 5 or 6 °C.

Read more: “Oases of cool: Taking the heat out of urban living“

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