1°C warming is actually 2°C warming

Earth as a whole has warmed about 1°C since 1850-1900. And the goal of the Paris Agreement is to forestall 1.5°C or at least 2°C of warming. What is easy to overlook is that these numbers represent an average.

Oceans comprise 71% of earth’s surface and take longer to warm than land. They have indeed warmed about 1°C. Since 1979 land surface temperature – which affects us most directly – has risen about double that of ocean surface temperatures. According to NASA, since the year 2000, land temperature changes are 50% greater in the U.S. than ocean temperature changes; two to three times greater in Eurasia and three to four times greater in the (Ant)Arctic.

So when scientist discuss “preventing 2°C of global warming” they are really talking about forestalling around 3°C to 6°C warming on most land surfaces.

Figure: Warming in 2 RCP-scenario’s. Source: IPCC Climate Change 2014 Synthesis Report

The Arctic warms fastest; a phenomenon known as ‘Arctic amplification’ (see figure above). This is also supported by paleoclimatologic data: In the early Eocene (54-48mln years ago), while sea surface temperature at the tropics was about 6°C warmer, at the poles it was about 14°C warmer.

Different places and surfaces warming at different speed will have huge consequences. For example, the just mentioned reduction of the difference between temperature at the tropics and the poles, the ‘Equator-to-pole surface temperature gradient’ (from e.g. 28°C now to 20°C), has been linked to changes in ocean circulation, behaviour of the jet stream, and the shifting of the Intertropical Convergence zone (ITCG) – determining a.o. Sahel rainfall, tropical storm activity and Californian drought.

Migrate northward or southward?

Where will you migrate to in the face of climate change? Will you go to a country in the Southern Hemisphere (> 45th parallel): New Zealand or Chile maybe? Or will you go to a country in the Northern Hemisphere (> 50th parallel): Canada, Russia or the Scandinavian countries? Which of the two will it be?

Earth’s land mass is mainly located in the Northern Hemisphere (67,3% of the total). Almost 40% of the Northern Hemisphere’s surface is land, against 19,1%  of the Southern Hemisphere (of which 5,5% is Antarctica).

Also, the main continents of the world are funnel-shaped. The further South you go, the less room there is. The 45th South Parallel passes for 97% through open ocean. The 60th  South Parallel does not ever hit land. More warming means that the habitable zones in the Southern hemisphere will get smaller. In the North there are – still – huge swaths of land.

Figure: Cumulative land mass by Latitude, source: andywoodruff.com

The Southern Hemisphere will warm less, because of a greater body of water and the Antarctic. The North is predicted to be up to 1.6°C warmer than the South on a Business As Usual emissions-trajectory. Also, the energy it costs to melt Antarctic ice sheets can, depending on how fast the West Antarctic ice sheet disintegrates,  delay future warming in cities such as Buenos Aires and Cape Town by 10-50 years.

Contraintuitively, the warmer North may be bad news for the South. Tropical rain bands tend to favor the warmer Hemisphere and may thus shift Northward, drying out parts of the Southern Hemisphere. At the same time, the behavior of the gulf stream and polar jet stream – and subsequent erratic weather patterns – in the Northern Hemisphere is still up for grabs.

More than 4°C warming? Homo homini lupus est

A premise of this website is that the earth will warm by approximately 4°C by the end of this century. But what if it will be more? The amount of possible feedback loops (permafrost thawing, boreal and tropical forests burning, et cetera), adjusted climate models, oceans that have absorbed more heat than previously thought and the ‘faster than expected’ mantra we keep hearing every week, make it ever more plausible that by the end of the century the earth will be spiraling up towards a ‘hothouse earth’.

So, where to migrate to then? The best advice is probably to get away from the masses. If things get really bad food will be scarce and people tend to turn on one another. The director of the Potsdam Institute for Climate Impact Research declared that at 4°C warming “It’s difficult to see how [the earth] could accommodate a billion people or even half of that.” In such or worse scenarios horde after horde of desperate people will plunder and try to hold any piece of viable land and the very limited resources that are left.

Canada and Russia are both massive and sparsely populated. A warmer climate might mean more agricultural possibilities in these countries. So moving there might offer the best chances for survival. Although, with no Arctic sea ice and a meandering (polar) jet stream, conditions might get worse even there.

Figure: The Guardian, may 2019.

Or, counterintuitively, go to a place where people will definitely not flock to. The Siberian and Inuit people still exist because other people were not interested in their land and scarce resources, while mainstream native Americans had to bear the full brunt of colonization. Would you rather struggle against nature or against your fellow man? As some users of the subreddit r/collapse suggest: “So go to a desert or to the Antarctic. Pick the most inhospitable place possible, were it’s not just hard to survive, but a life or death struggle even for the prepared. Congratulations, come collapse of civilization you will not have to worry about looters since they’ll never survive to get there. The environment will be your only foe and you will be well adjusted before and ready as can be before the rest collapses.