Climate in Context: Facing Off With Climate Skeptics; Arctic Ice Melting Affects Phytoplankton

Schneider, 1: Skeptics, 0

Shortly before his untimely death in July at the age of 65, Stephen Schneider, a renowned climate scientist from Stanford University, fielded questions from a room full of climate change skeptics in Sydney, Australia. As part of the television show Insight, on Australia’s SBS public broadcasting network, Schneider faced a barrage of questions about the existence of man-made climate change and uncertainties in climate science from an audience of non-scientists. And one by one, Schneider managed to fend off their doubts with clear and concise (and for the most part, patient) answers on what the scientific evidence shows. It even seems that by the end of the hour-long show, he managed to change the minds of some of those in the audience.

Click to view the episode of Insight with Stephen Schneider. Credit: SBS.

We put this in the same category as the Skeptical Science iPhone app – a great resource when you’re not sure what to say to your friends who say that yesterday’s snowfall is proof that the Earth isn’t getting hotter.

Arctic Phytoplankton Bloom Changes with Melting Sea Ice

Considering their small size (microscopic, actually), phytoplankton sure are getting a lot of attention these days. Recent research has suggested that large swaths of these tiny plant-like marine microbes have been wiped out in recent decades, possibly due to rising ocean temperatures. Now, a new study has found that earlier summer melting of Arctic sea ice during the last decade has changed the growth patterns of phytoplankton, which may have some affect on the food chain of animals living in northern regions.

Researchers from Scripps Institution of Oceanography, with collaborators from Lisbon, Portugal and Mazatlán, Mexico, monitored the time in the summer when phytoplankton populations in the Arctic begin to grow rapidly, or bloom. They found that the bloom is occurring as many as 50 days earlier than what was observed in 1997, though the exact dates change from year to year. The authors claim that this advance in the annual bloom coincides with the earlier retreat of sea ice in the area, which is linked to warmer Arctic temperatures.

Just like many of the other recent studies that indicate climate change is causing problems for the oceans’ phytoplankton, this paper says that the consequences of changes to phytoplankton blooms are likely to trickle up through the food chain, though the study doesn't offer much evidence to support this. In the Arctic it is possible that if the bloom occurs much earlier than in the past, the animals that feed on phytoplankton will miss their opportunity to chow down if they are expecting the bloom to occur later in the season.

The relationship between sea ice melting and phytoplankton populations isn’t completely known, though. This same study also found there was not a clear correlation between sea ice retreat and the timing of phytoplankton blooms south of the Arctic in the Atlantic Ocean, even though some of these areas experienced much earlier sea ice retreat than in the Arctic.