A.2}
Climate change has caused substantial damages, and increasingly 
irreversible75 losses, in terrestrial, freshwater, cryospheric and 
coastal and open ocean ecosystems (high conﬁdence). The extent 
and magnitude of climate change impacts are larger than estimated 
in previous assessments (high conﬁdence). Approximately half of the 
species assessed globally have shifted polewards or, on land, also to 
higher elevations (very high conﬁdence). Biological responses including 
changes in geographic placement and shifting seasonal timing are often 
not sufﬁcient to cope with recent climate change (very high conﬁdence). 
Hundreds of local losses of species have been driven by increases in 
the magnitude of heat extremes (high conﬁdence) and mass mortality 
events on land and in the ocean (very high conﬁdence). Impacts on 
some ecosystems are approaching irreversibility such as the impacts 
of hydrological changes resulting from the retreat of glaciers, or the 
changes in some mountain (medium conﬁdence) and Arctic ecosystems 
driven by permafrost thaw (high conﬁdence). Impacts in ecosystems 
from slow-onset processes such as ocean acidiﬁcation, sea level rise 
or regional decreases in precipitation have also been attributed to 
human-caused climate change (high conﬁdence). Climate change 
has contributed to desertiﬁcation and exacerbated land degradation, 
particularly in low lying coastal areas, river deltas, drylands and in 
permafrost areas (high conﬁdence). Nearly 50% of coastal wetlands 
have been lost over the last 100 years, as a result of the combined 
effects of localised human pressures, sea level rise, warming 
and extreme climate events (high confidence).