Hundreds of millions of global poor will be affected by warming oceans

By Jeff Spross on 24 October 2013

Climate Progress

The damage climate change will do to the oceans could be disastrous for the world’s poorest, according to a new study.

Humanity’s greenhouse gas emissions will alter the oceans in several ways, including shifts in ocean temperature, reduced oxygen concentrations, and higher acidity as they absorb more carbon dioxide from the atmosphere. To track how, a group of researchers lead by Camilo Mora, a geography professor at the University of Hawaii, ran 32 marine habitats around the world through a series of modeled simulations. They looked at what would happen to these areas until 2100, under both a “business as usual” scenario — in which carbon dioxide concentration in the atmosphere rises to 900 parts per million — and an alternative scenario in which humanity takes drastic action to cut those emissions.

“Our results suggest that the entire world’s ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity,” the researchers reported. “Only a very small fraction of the oceans, mostly in polar regions, will face the opposing effects of increases in oxygen or productivity, and almost nowhere will there be cooling or [decrease in acidity].”

These changes could very well reduce the oceans’ biological productivity. In particular, the models suggested a four to ten percent cut in the production of phytoplankton, which form the lowest foundation of most of the oceanic food chains. That in turn would mean “massive and challenging” ramifications for the 470 to 870 million poor people around the world who rely on the seas for their food and livelihoods. Many of them live in the countries that will be the hardest hit by the changes the researchers tracked.

This work follows up on a growing body of evidence detailing the unique threat climate change poses to the global poor. The problems extend well beyond ocean changes, to extreme weather and crop disruptions. Southern and southeastern Asia are home to a large portion of the global poor, and face destabilizing climate shifts, altered monsoon patterns, and floods. The World Bank has warned that within two decades, drought and rising heat could leave 40 percent of sub-Saharan Africa’s farmland unsuitable for growing maize or for grazing livestock.