Executive summary The health of the planet and its people are at risk. The deterioration of
the global commons—ie, the natural systems that support life on Earth—is exacerbating …

Volcanic eruptions have long been studied for their wide range of climatic effects. Although
global-scale climatic impacts following the formation of stratospheric sulfate aerosol are well …

This planetary boundaries framework update finds that six of the nine boundaries are
transgressed, suggesting that Earth is now well outside of the safe operating space for …

The stability and resilience of the Earth system and human well-being are inseparably
linked,–, yet their interdependencies are generally under-recognized; consequently, they …

Sahel rainfall is dynamically linked to the global Hadley cell and to the regional monsoon
circulation. It is therefore susceptible to forcings from remote oceans and regional land alike …

Human security will be progressively threatened as the climate changes (robust evidence,
high agreement). Human insecurity almost never has single causes, but instead emerges …

Interest in stratospheric aerosol and its role in climate have increased over the last decade
due to the observed increase in stratospheric aerosol since 2000 and the potential for …

Future changes in the position of the intertropical convergence zone (ITCZ; a narrow band of
heavy precipitation in the tropics) with climate change could affect the livelihood and food …

As atmospheric carbon dioxide concentrations rise and climate change becomes more
destructive, geoengineering has become a subject of serious consideration. By reflecting a …

Solar radiation modification (SRM) is a possible deliberate approach to decrease or reflect
incoming solar radiation with the goal of reducing global temperatures, which have …