World Met Day poster image

World Meteorological Day 2020

23 March 2020

World Meteorological Day is an annual event, celebrated on 23 March. It is recognition of the convention that resulted in the establishment of the World Meteorological Organisation (WMO). It also celebrates and recognises the substantial contribution national meteorological and hydrological services make to everyday life and society.

This year's theme for World Meteorological Day is Climate and Water. It is an extremely topical theme given the record breaking amounts of rainfall and subsequent flooding experienced in the UK during February 2020.

To mark the day, in our 170th year and WMO’s 70th year, Wiley have offered free access, until 20 April, to over 50 relevant articles - including some from our scientific journals. You can find all articles here.

We have also put together some important facts around the theme of climate and water, which we will be publishing on our Twitter feed throughout the day. Although, if you can’t wait for our hourly posts, you can have a sneak peek below:

  • Water and the hydrological cycle are integral to the climate system. In the Earth’s hydrosphere, 97.4% of water is distributed in the oceans, 2.0% in polar ice, sea ice and glaciers, and 0.6% in surface water, ground water and atmospheric water (Collier, 2016). #worldmetday
  • For every degree Celsius of warming, the atmosphere can accommodate up to 7% more water vapour (Henson, 2019). #worldmetday
  • Global warming will bring ‘increases in frequency, intensity and/or amount of heavy precipitation in several regions, and an increase in intensity or frequency of droughts in some regions’ (IPCC, 2018). #worldmetday
  • Between 2015 and 2100, global mass reductions in glaciers are predicted to range from 18% (±7%) for a low emissions scenario, to 36% (±11%) for a high emissions scenario (IPCC, 2019). #worldmetday
  • Water in its liquid and gaseous states has very different albedos. The ocean typically reflects 2-10% of incoming solar radiation, whilst ice and fresh snow reflect 20-70% and 70-80% resp. Changes in albedo can have a significant impact on climate (Wells, 2011) #worldmetday
  • ‘The global ocean has warmed unabated since 1970 and has taken up more than 90% of the excess heat in the climate system’ (IPCC, 2019). The warmer the ocean gets, the less CO2 it can absorb, leaving more CO2 in the air to stimulate further warming (Henson, 2019). #worldmetday
  • Global Mean Sea Level is currently rising at around 3.6cm per decade; primarily a result of thermal expansion and the melting of ice sheets and glaciers (IPCC, 2019). #worldmetday
  • By 2100, The Intergovernmental Panel on Climate Change predicts that global mean sea level will likely lie between 29-59cm under a low emissions scenario or 61-110cm under a high emissions scenario (IPCC, 2019). #worldmetday
  • The Atlantic Meridional Overturning Circulation transports warm, salty water northwards and cold, denser water southward. During the 21st century, it is projected to weaken under all emission scenarios (IPCC, 2019), resulting in various changes to global climate. #worldmetday
  • Water has a higher specific heat capacity than dry soil, meaning more energy is required to heat 1kg of water by 1oC than for dry soil. Thus, on a local scale, proximity to water results in a more moderate climate with a smaller temperature range versus that inland. #worldmetday
  • It is thought that by limiting global warming to 1.5oC rather than 2oC, we could reduce the population exposed to climate-induced water stress by up to a half (IPCC, 2018). #worldmetday
  • Changing temperatures, rainfall and sediment loads are just a few of the factors predicted to reduce water quality under climate change (IPCC, 2014). #worldmetday



Collier, C. G., 2016: Hydrometeorology. Wiley-Blackwell, 376pp.

Henson, R., 2019: The Thinking Person’s Guide to Climate Change. 2nd Ed., American Meteorological Society, 516pp.

IPCC, 2014: Summary for policymakers. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R. Mastrandrea, and L.L.White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1-32.

IPCC, 2018: Summary for Policymakers. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. World Meteorological Organization, Geneva, Switzerland, 32 pp.

IPCC, 2019: Summary for Policymakers. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. In press.

Wells, N. C., 2011: The Atmosphere and Ocean: A Physical Introduction. 3rd Ed., Wiley-Blackwell, 424pp.