The environmental effects of climate change are broad and far-reaching, effecting oceans, ice, and weather. Changes may occur gradually or rapidly. Evidence for these effects comes from studying climate change in the past, from modelling, and from modern observations.[131] Since the 1950s, droughtsand heat waves have appeared simultaneously with increasing frequency.[132] Extremely wet or dry events within the monsoon period have increased in India and East Asia.[133] Various mechanisms have been identified that might explain extreme weatherin mid-latitudes from the rapidly warming Arctic, such as the jet stream becoming more erratic.[134]The maximum rainfall and wind speed from hurricanes and typhoons is likely increasing.[135]

Climate change has led to decades of shrinking and thinning of the Arctic sea ice, making it vulnerable to atmospheric anomalies.[136] Projections of declines in Arctic sea ice vary.[137] While ice-free summers are expected to be rare at 1.5 °C (2.7 °F) degrees of warming, they are set to occur once every three to ten years at a warming level of 2.0 °C (3.6 °F),[138]increasing ice–albedo feedback.[139]

Global sea level is rising as a consequence of glacial melt, melt of the ice sheets in Greenland and Antarctica, and thermal expansion. Between 1993 and 2017, the rise increased over time, averaging 3.1 ± 0.3 mm per year.[140] Over the 21st century, the IPCC projects that in a very high emissions scenario the sea level could rise by 61–110 cm.[141] Increased ocean warmth is undermining and threatening to unplug Antarctic glacier outlets, risking a large melt of the ice sheet[142] and the possibility of a 2-meter sea level rise by 2100 under high emissions.[143]