Climate Change and the Hydrological Cycle: A Pit-stop Tour.

Climate change is an all too familiar phrase that is often accompanied by a profound, and yet distant, sense of dread. However the effects of climate change are already taking place, and it is widely agreed that Africa is experiencing temperature rises higher than any other continent. It’s important to understand the mechanisms behind climate change to understand it’s effects on the hydrological cycle and, ultimately, the African population.

Climate Change.

Earth’s climate has been widely variable throughout its history, from the humid ‘super greenhouse’ of the Eocene to a completely frozen planet known as ‘Snowball Earth’. These changes have taken place over timescales that range from thousands to millions of years and have been influenced by numerous factors including the Milankovitch cycles (which describe cyclical variations in the Earth’s orbit) and factors influencing the Earth’s energy budget such as solar variations, volcanic activity and greenhouse gases (GHG’s). The influence of these factors can be measured by their radiative forcing. The current, rapid change in climate, which has an observed increase of 0.2^oC/decade since 1970, cannot be majorly attributed to any forcing other than anthropogenic.

Humans, and their friendliness with fossil fuels, have caused a dramatic increase of atmospheric CO₂ concentrations over recent decades. CO₂ is a GHG, therefore it is absorbing of outgoing radiation and offsets the global energy budget. The way that the Earth system responds to this gain in energy is by radiating it as heat (which is known as the Blackbody response), hence the upwards drive in global temperatures. The general consensus is that we are due to exceed the 1.5^oC target set by the Paris agreement in the next few decades, how much the planet warms past that is complete up to efforts to reduce emissions hand in hand with mitigating the impacts.

The Effects of Climate Change on The Hydrological Cycle in Africa.

My fully formed response to this statement is going to be explored throughout the duration of this blog, but the general relationship between global warming and the hydrological cycle is that wet places will get wetter and dry places will get drier. Africa’s hydrological systems vary so much throughout the continent, with much of the central landmass spanning the humid tropics while areas such as the Sahel have a semi-arid climate and rely on seasonal rainfall. With this knowledge, it is obvious to state that with much of the continent already experiencing climatic extremes, the furthering of these extremes that climate change is set to cause has huge implications for flooding, droughts, and humanity.

Now we’ve established a general understanding of climate change and the broad implications on the hydrological cycle, I’m excited to discuss these concepts in further detail and ruminate on mitigation and adaption strategies.

Until next time!