If a large 
explosive volcanic eruption were to occur in the near term150 , it 
would temporarily and partially mask human-caused climate change 
by reducing global surface temperature and precipitation, especially 
over land, for one to three years (medium conﬁdence). {WGI SPM B.1.3, 
WGI SPM B.1.4, WGI SPM C.1, WGI SPM C.2, WGI Cross-Section Box TS.1, 
WGI Cross-Chapter Box 4.1; WGII SPM B.3, WGII SPM B.3.1; 
WGIII Box SPM.1 Figure 1}
The level of risk for humans and ecosystems will depend on near-term 
trends in vulnerability, exposure, level of socio-economic 
development and adaptation (high conﬁdence). In the near term, 
many climate-associated risks to natural and human systems depend 
more strongly on changes in these systems’ vulnerability and exposure 
than on differences in climate hazards between emissions scenarios 
(high conﬁdence). Future exposure to climatic hazards is increasing 
globally due to socio-economic development trends including growing 
inequality, and when urbanisation or migration increase exposure 
(high conﬁdence). Urbanisation increases hot extremes (very high 
conﬁdence) and precipitation runoff intensity (high conﬁdence). 
Increasing urbanisation in low-lying and coastal zones will be a major 
driver of increasing exposure to extreme riverﬂow events and sea level 
rise hazards, increasing risks (high conﬁdence) (Figure 4.3). Vulnerability 
will also rise rapidly in low-lying Small Island Developing States and 
atolls in the context of sea level rise (high conﬁdence) (see Figure 3.4 and 
Figure 4.3). Human vulnerability will concentrate in informal settlements 
and rapidly growing smaller settlements; and vulnerability in rural 
areas will be heightened by reduced habitability and high reliance on 
climate-sensitive livelihoods (high conﬁdence). Human and ecosystem 
vulnerability are interdependent (high conﬁdence).