“Geoengineering” refers to technologies that people might use to intentionally alter the planet’s climate system to address the threat of global warming. One of the most frequently discussed approaches is solar geoengineering – blocking some of the sun’s energy by, for example, injecting tiny particles into the atmosphere. But solar geoengineering is controversial. Some experts argue that it is a relatively cheap and quick fix for rising temperatures, the most pressing aspect of climate change. But critics point to potential negative side effects that could result from manipulating the climate in this way.