The Washington PostDemocracy Dies in Darkness

The whole globe is warming — but look at how much of it is caused by the Northern Hemisphere

Category 5 Cyclone Pam about to make landfall in Vanuatu. <a href="">NASA</a>

Two climate change stories from the last month:

* After a devastating Category 5 landfall from Cyclone Pam, Vanuatu President Baldwin Lonsdale controversially suggested that climate change was contributing to the disasters his nation has faced, including sea level rise and “cyclone seasons.”
* Troubling new research suggested that a warming climate may be contributing to the destabilization of the Totten Glacier of East Antarctica, which holds back so much ice that its melting could ultimately unleash 11 feet of sea level rise.

Whether or not Lonsdale’s statements are justifiable — at least one climate scientist sees a partial climate influence on Cyclone Pam — both of these events took place, or are taking place, in the southern hemisphere. Which certainly doesn’t mean they can’t be linked to climate change — after all, it’s global warming.

What’s striking, though, is how much of the global warming problem emanates from the the other half of the planet. The top side.

Consider this visualization, from the Post’s Kennedy Elliott, which is based on data from NOAA’s Earth System Research Laboratory:

“The Northern Hemisphere, home to almost 90 percent of the world’s population, is where the majority of atmospheric carbon dioxide originates,” writes Elliott. Indeed, of the world’s top ten cumulative greenhouse gas emitters from 1850 to 2011, only two, Brazil and Indonesia, are at least partly situated the southern hemisphere (and each has contributed about 1 percent of the global total).

These are not just idle observations — the situation has significant implications for the difficult international politics of climate change.

As the world seeks to achieve a global climate agreement in Paris later this year, one major issue will involve the calls from small island nationsAfrican nations, and numerous other states for even stronger greenhouse gas cuts than many major industrialized nations have thus far been willing to accept.

These nations, which have contributed very little to the climate problem by way of emissions but are nonetheless greatly affected by it, think we need to keep global warming below 1.5 degrees Celsius, rather than the more generally accepted target of 2 degrees C. (For an argument suggesting that the 2 degrees target is “utterly inadequate,” see here.)

It’s not that all Northern Hemisphere countries support 2 degrees and all southern hemisphere countries support 1.5 degrees. It’s not that simple. But there are clearly more supporters of the latter target below the equator, ranging from the Cook Islands and Vanuatu to South Africa and Madagascar. (For a list of the countries supporting the two targets, see Appendix 1 here.)

So in December, if you start hearing about difficulties in the negotiations in Paris, keep this map in mind.