Scientists are slowly starting to get practical on geoengineering. Cooling the entire planet with stratospheric solar geoengineering could cost only 5 billion dollars per year. And opting for artificial clouds saving the Arctic with geoengineering could be as cheap as 24 million euros.
Now a group including renowned climatologists and leading geoengineering thinkers Ken Caldeira and David Keith tries to investigate ways to alleviate some of the (likely) unwanted side effects of Arctic solar geoengineering.
The second-largest mass extinction in Earth’s history coincided with a short but intense ice age during which enormous glaciers grew and sea levels dropped. Although it has long been agreed that the so-called Late Ordovician mass extinction — which occurred about 450 million years ago — was related to climate change, exactly how the climate change produced the extinction has not been known. Now, a team led by scientists at the California Institute of Technology (Caltech) has created a framework for weighing the factors that might have led to mass extinction and has used that framework to determine that the majority of extinctions were caused by habitat loss due to falling sea levels and cooling of the tropical oceans.