Contents

About the author ii General overview 2021 2

1. Air temperatures 4Surface: spatial pattern 4 Lower Troposphere: monthly 6 Lower Troposphere: annual means 7 Surface: monthly 8 Surface: annual means 10 Error, consistency and quality 11 Surface versus lower Troposphere 14Lower Troposphere: land versus ocean 15 By altitude 16 Zonal air temperatures 17 Polar air temperatures 18
2. Atmospheric greenhouse gases 19Water vapour 19 Carbon dioxide 20
3. Ocean temperatures 22Recent surface temperature anomalies 22 By latitude 24 By depth 25 By region and depth 27 Ocean temperature net change 2004–2020 in selected sectors 28
4. Ocean oscillations 31Southern Oscillation Index 31 Pacific Decadal Oscillation 31 Atlantic Multidecadal Oscillation 31
5. Sea-level 33In general 33 From satellite altimetry 34 From tide gauges 35 Modelled for the future 36
6. Snow and ice 39Global, Arctic and Antarctic sea ice extent 39 Northern Hemisphere snow cover extent 41
7. Storms and wind 43Accumulated cyclone energy 43 Other storm and wind observations 45
8. Written references 46
9. Links to data sources 46

Review process 50 About the Global Warming Policy Foundation 50

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