Warming appears to have gone into overdrive, with the northern hemisphere going 2°C above pre-industrial temperatures for the first time, says Eric Holthaus

Unusually warm Frank Olsen/Getty

Preliminary February and early March temperatures are in, and it’s now abundantly clear: warming is going into overdrive.

As of 3 March, it appears that average temperatures across the northern hemisphere breached 2°C above pre-industrial levels for the first time in recorded history, and probably the first time since human civilisation began thousands of years ago.

The 2°C mark has long been held (somewhat arbitrarily) as the point above which climate change may begin to become “dangerous” to humanity. It has now arrived – though very briefly and only in the northern hemisphere – much more quickly than anticipated. This is a milestone moment for our species. Climate change deserves our greatest possible attention.


As for the planet as a whole, there are dozens of global temperature datasets, and usually I (and other climate journalists) wait until the official ones are released to announce a record-breaking month at the global level. But February’s global data is so extraordinary that there is no need to wait: it obliterated the all-time temperature record set only in January.

Using unofficial data and adjusting for different baseline temperatures, it appears that February was somewhere between 1.15°C and 1.4°C warmer than the long-term average, and about 0.2°C above January – making it the most above-average month ever measured. (Since the globe had already warmed by about 0.45°C above pre-industrial levels during the 1981-2010 baseline meteorologists commonly use, that amount has been added to the data.)

Stunning rise

Keep in mind that it took from the dawn of the industrial age until October 2015 to reach the first 1.0°C rise. That means we have come as much as an extra 0.4°C further in just the last five months. Even accounting for the margin of error associated with these preliminary datasets, that means it is virtually certain that February beat the record set in January for the most anomalously warm month for the entire globe ever recorded. That’s stunning.

It also means that for many parts of the northern hemisphere, there basically wasn’t a winter. Parts of the Arctic were more than 16°C warmer than average for February, bringing them a few degrees above freezing, on par with typical June temperatures, in what is often the coldest month of the year.

In the US, the winter was record-warm in cities coast to coast. In Europe and Asia, dozens of countries set or tied their all-time temperature records for February. In the tropics, the record-warmth is prolonging the longest-lasting coral bleaching episode ever seen.

The northernmost permanent settlement, Norway’s Svalbard archipelago, has averaged 10°C above what is usual in winter, with temperatures rising above freezing on 21 days since 1 December. That kind of extremely unusual weather has prompted a record-setting low in the maximum extent of Arctic sea ice, especially in the Barents Sea.

Sceptical converts

The data for February is so overwhelming that even prominent climate change sceptics have embraced the record. Writing on his blog, former NASA scientist Roy Spencer said that according to satellite records – the dataset of choice by climate sceptics for a variety of reasons – February featured “whopping” temperature anomalies, especially in the Arctic.

Spurred by disbelief, Spencer checked his data with others and said the overlap is “about as good as it gets”. Speaking with The Washington Post, Spencer said the February data proves “there has been warming. The question is how much warming there’s been.”

Of course, all this is happening in the context of a record-setting El Niño, which tends to boost global temperatures for six or eight months beyond its usual peak at the end of the calendar year – mainly because it takes that long for excess heat to filter its way across the planet from the tropical Pacific Ocean.

But El Niño isn’t entirely responsible for the absurd numbers we are seeing. Its influence on the Arctic still isn’t well-known and is probably small. In fact, El Niño’s influence on global temperatures as a whole is likely to be small – on the order of 0.1°C or so.

No more normal

What’s actually happening now is the liberation of nearly two decades’ worth of global warming energy that has been stored in the oceans since the last major El Niño in 1998.

Numbers like this amount to a step-change in our planet’s climate system. Peter Gleick, a climate scientist at the Pacific Institute in Oakland, California, said it is difficult to compare the current temperature spike: “The old assumptions about what was normal are being tossed out the window… The old normal is gone.”

Almost overnight, the world has moved within arm’s reach of the climate goals negotiated just last December in Paris. There, small island nations on the front line of climate change set a global temperature target of no more than 1.5°C rise by the year 2100 as a line in the sand, and that limit was embraced by the global community.

On our current pace, we may reach that level for the first time – though briefly – later this year. In fact, for individual days, we are probably already there. We could now be in the heart of a decade or more surge in global warming that could kick off a series of tipping points with far-reaching implications on our species and the countless others we share the planet with.

This article first appeared on Slate