Governments all over the world are promising to plant billions of trees to help fight climate change, but restoring whale populations could be a more effective way of reducing levels of atmospheric CO2. Whales, studies have found, are natural carbon sinks. Humpback and Minke whales can absorb up to 30,000 kg of carbon and when they die they take it to the bottom of the ocean. By contrast trees typically absorb 21kg a year, which is likely to be returned to the atmosphere much sooner.
Whales also feed on plankton, which are then expelled as excrement, when they surface. This releases a plume of nutrients into the water, which stimulates the growth of phytoplankton-algae that absorbs carbon from the air via photosynthesis. In aggregate phytoplankton captures the same amount of carbon as 1.7 trillion trees (or four Amazon rain forests worth). According to the new IMF report, increasing phytoplankton productivity by just 1% would have the same impact on levels of CO2 as conjuring up 2 billion mature trees!
WDC, Whale and Dolphin Conservation