CARE2022 Hong Kong Conference

12 • Global warming of 1.5°C and 2°C (as per the Paris Agreement) will be exceeded unless deep reductions in CO2 and other GHGs occur in the coming decades. The current best estimate is that the global air temperature will rise by about 2.5°C to 3°C above the pre-industrial level by the end of this century. • 3°C global warming is a major risk for food security due to a loss of crop yield in most parts of the world. Water security will also be a major challenge due to global warming and population growth. • Global sea level has been rising at an increasing rate and given the current high GHG concentration level, melting of glaciers and sea level rise will continue in the coming hundreds of years. • To get on track, the world would need to reduce CO2 and other GHGs by unprecedented levels over this decade and emissions must continue to decline rapidly to reach carbon neutrality by 2050. Even though the worst-case scenario of 3°C to 5°C warming previously projected by the Fifth Assessment of IPCC (AR5) might be avoided, there will still be a major challenge in mitigation. • Continued global warming is projected to intensify the global water cycle, including its variability, global monsoon precipitation and the severity of wet and dry events. • Heatwaves, heavy precipitation, and droughts are projected to be larger in frequency and intensity with every additional increment of global warming. • Every region will experience concurrent and multiple changes in climatic impact-drivers at higher levels of global warming. Prof. Taalas also highlighted several global initiatives of the WMO in supporting the United Nations in combating climate change, including to achieve 100% implementation by WMO Members of multi-hazard early warning services and impactbased weather forecasting, enhancements of meteorological and hydrological observing systems, and monitoring of GHG in the atmosphere, and improvements of global climate modelling and prediction. 2 Climate Science – “Our climate is our future” FIGURE 2.1 Observed global mean surface temperature change relative to 1850-1900 1.4 1.2 1 0.8 0.6 0.4 0.2 0 -0.2 GMST Change ºC 0.00°C (1850-1900) 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year Pre-industrial likely range 1.26°C (2020) 1.12-1.37 1.09°C (2011-2020) 0.95-1.20 0.85°C (1995-2014) 0.69-0.95 0.69°C (1986-2005) 0.54-0.79 0.58°C (1980-1999) 0.45-0.68 0.36°C (1961-1990) 0.23-0.44 0.23°C (1900-1999) 0.10-0.31