Climate science attempts to answer a lot of questions, but Earth’s population probably cares about just one of them: what is the amount of global warming we should expect from a given amount of greenhouse gas emissions?

There are a variety of metrics researchers use to describe that variable, differing mainly in how long you give the climate system to equilibrate. One handy metric is called the “transient climate response to cumulative carbon emissions”—TCRE for short. Given a total amount of CO 2 emitted up until a point in time, this relationship tells you about how much warming will have already occurred.

It’s a straightforward and (nearly) linear relationship that was highlighted in the last Intergovernmental Panel on Climate Change report. Find your place on the graph by totaling up historical CO 2 emissions and you get an idea of how much of the “carbon budget” remains before you reach, say, 2°C warming.

But this number is an average across the entire globe; we should expect significant regional differences. A new study led by Martin Leduc and Damon Matthews at Concordia University in Montreal produced something simple but interesting: a map of how TCRE varies around the world.

The researchers used simulations from 12 complex climate models that include things like the carbon cycle. In the simulations, the concentration of carbon dioxide in the atmosphere was increased by one percent each year until it reached four times the pre-industrial level. Rather than work only with globally averaged temperature changes, Leduc and Matthews calculated short-term climate sensitivities at a local scale.

They got an average global TCRE of 1.7 ±0.4 °C per thousand gigatonnes of carbon in CO 2 emissions—smack in the middle of the range from the last IPCC reports (no surprise, given the IPCC also used these simulations). For reference, we have emitted over 550 gigatonnes so far and are adding around 13 gigatonnes per year. If you give the climate system a little longer to equilibrate, more warming will occur, but this sensitivity describes the temperature of the planet right now.

Separating land areas from the ocean shows how much more slowly the oceans warm due to their tremendous heat capacity and constant circulation. Ocean TCRE averaged 1.4 ±0.3 °C per thousand gigatonnes of carbon emitted, while land areas averaged 2.2 ±0.5°C and mostly fell between 1.5 and 4°C.

Equatorial regions warm the slowest, while the Arctic warms the fastest. Of course, this is what we’ve already seen happen—rapid changes in the Arctic are outpacing the rest of the planet.

While the global TCRE is basically a linear relationship up to two thousand gigatonnes of carbon emitted, it does begin to drop off slightly toward the high end, partly because the warming potential of added CO 2 decreases as the atmosphere gets crowded with it. But by examining regional relationships, the researchers found that one region was responsible for a large part of that deviation—the Barents and Kara Seas north of Russia.

The team suggests two possible explanations. First, the warming feedback caused by the loss of reflective snow and sea ice weakens as the remaining area of snow and ice shrinks. And second, changes in ocean currents bring less warm water up to this region over time.

Apart from that interesting detail, the study provides another way for you to think about the warming projections in your neck of the woods relative to the rest of the planet. The researchers note this approach could even be used to help figure out how much blame for local-scale changes can be pinned on global greenhouse gas emissions.

Nature Climate Change, 2016. DOI: 10.1038/nclimate2913 (About DOIs).

Listing image by Leduc, Matthews, Elía, Nature Climate Change