FYI.

This story is over 5 years old.

Tech

Warming Oceans Are Forcing Marine Animals to the Poles, But They Can't Move Fast Enough

For the past four decades marine animals have been moving poleward at over four miles a year.
Photo: USFWS/Flickr

We've gained some new insight into how well animals are and will be able to adapt as the planet continues to warm from a new piece in Nature Climate Change. In it, scientists conducting a meta-analysis of how marine animals are responding to warming oceans found that marine life is moving towards the poles much faster than their land-dwelling brethren—twelve times faster in fact.

"The leading edge of marine species are moving toward the poles at an average of 72 kilometers (45 miles) per decade," lead author Elvira Poloczanska told Science Recorder. The average the start of spring migrations for marine animals is now starting four days earlier than they did four decades ago.

Advertisement

That compares to an average poleward migration of just six kilometers (3.7 miles) per decade for land animals, with spring migrations beginning two days earlier than they did in the early 1970s. All of this is happening against the backdrop of sea surface temperatures warming three times more slowly than land temperatures.

Why does this matter? For many oceanic species, they only have so much space to roam. For example, a species in the Mediterranean can only go so far northward before they run out of ocean, which means those individuals may not be able to escape warming waters.

Looking at temperature rise in the United States, from 1970 through 2011 warming occurred three times more quickly than it did in the previously hundred years, happening now at a rate of 0.44°F per decade.

Broadening things out to the global scale, the latest global analysis from the National Climatic Data Center shows global land surface temperatures for the month of June were 1.89°F (1.05°C) above average, with global ocean surface temperatures being 0.86°F (0.48°C) above average. Within a few hundredths of a degrees that's consistent with the data for the January to June period this year.

That animals are already moving poleward in response to climate change is interesting, and expected (they'll also attempt to move to higher elevations where possible). This sort of migration increasingly looks like it won't be enough, for many species.

Research published two months ago shows that many animals will need to move far more quickly than they are now, or evolve 10,000 times more quickly to new climatic conditions than they ever have before.

A recent study found that, on average, species have adapted to new climate conditions at a rate of about 1°C per million years. Given the speed with which human activity is increasing average global temperature—at least 4°C above pre-Industrial levels by the end of this century—and the level of habitat fragmentation as human population and developments increase, it's just not a bright future for many wild species.