Apart from a few die-hard conspiracy theorists, there is worldwide acceptance that climate change is happening, and that it is caused by greenhouse gas emissions (GHG) mainly from fossil fuel burning, but also cement production, deforestation and agriculture.

To make a ‘climate forecast’ of the future, we need to know two key things: firstly, what will future emissions be, and secondly, how will global and regional climate systems respond to these emissions? Both are impossible to forecast precisely (or even close to precisely). But we can – and should – estimate likely possible futures and use these to plan responses.



The climate response to GHG emissions is uncertain because science has not yet managed to pin down some key feedbacks and related processes in the climate system.

Most of these feedbacks are positive – that is, as the climate warms, they respond to make the climate even warmer. For example, as the atmosphere warms, it evaporates and retains more water vapour, which is itself a powerful natural GHG. This leads to more warming, and then more evaporation, and so on. Other positive feedbacks include the effects of melting snow and ice in the polar regions and probably natural CO2 storage on land and in the oceans. Science has managed to scope the range of responses from the feedbacks, but this is still quite large. For example, for a doubling of CO2, the likely global temperature change is in the range of 1.5-4.5 degrees Celsius (°C).

The extent of future emissions depends on the global political economy, and the way it responds to the threat of climate change. The worst case scenario is that of ‘business as usual’, where there is minimal action taken to reduce humanity’s impact on the climate, with GHG emissions rising at the same compound rate as they have in the past, out to 2100, until all the easily mineable coal, oil and gas have been used or become too expensive. If this pans out, we are looking at a global temperature change of 3.5°C - 6.0°C over preindustrial temperatures.

Thankfully, most organisations and people who are tracking action on climate change think this is unlikely. This is firstly because alternatives to fossil fuels are becoming cheaper. Solar electricity is already cheaper than coal-fired energy, and other renewables are approaching parity. Simple economics means that an increasing proportion of new electricity generation will be low carbon. It is likely that transport energy will also at some time in the future be fossil-fuel free, but this may only realistically occur at scale in the second half of this century. There is certainly unprecedented investment in alternative energy research, and at least some of the possibilities under investigation are likely to come good.

Also, political will seems at last to be shifting. The promises by governments at the 2015 Paris Climate Change Conference, if implemented, are on track to keep global temperatures in the range 2.2°C - 3.4°C, with a best estimate of 2.7°C. If one looks only at the policies that have actually been implemented, then this range creeps up to 2.6°C - 4.9°C, with a best estimate of 3.6°C. However, even the most optimistic analysts think it is unlikely that emissions will decline steeply enough to keep temperatures below the 2°C target, let alone the 1.5°C ambition agreed at Paris; so significant levels of warming are definitely on the cards. THE AFRICA FORECAST Climate change over Africa depends on how the global warming signal is propagated through regional climate processes to the different parts of the continent. Africa is likely to warm at one-and-a-half to two times the average global warming rate, because land areas warm faster than the oceans, and over land drier areas warm faster than wetter areas. Unfortunately, most of Africa outside of the tropics is pretty dry already. So, for example, the global warming of 2.9°C that might arise from the pledges of the Paris agreement would result in a warming of 4.3°C-5.8°C over the interior of Southern Africa.

Changes in rainfall are harder to forecast, because rainfall is a function of many more interacting atmospheric factors than temperature. Nonetheless, there is a fairly consistent picture that across Africa, the sub-tropics will get drier and the tropics wetter. The Mediterranean climates at the northern and southern edges of the continent – watch out Cape Town – are also likely to become drier.

Sea level rise – expected to be between 20cm-40cm by 2050, and double that by the end of the century – poses severe risks to coastal settlements, with increased coastal erosion, inundation and salt water intrusion.

Weather extremes are likely to become more severe; climate scientists have already been able to show a human ‘signature’ in the changed risk of heat stress in heatwaves, and in some drought events. A remaining uncertainty is how El Nino and other natural drivers of year-to-year variations in weather and climate will change as the planet warms. However, they are unlikely to disappear, and so will continue to impose themselves on a warming background state of the climate. For example, the recent El Nino, superimposed on the underlying global warming trend, has made the 11 months up to June 2016 the hottest on record globally. Over southern Africa, four of the last six months are also the warmest on record.


Low carbon energy is an absolute no-brainer for Africa, and so is an immediate investment opportunity. As African economies develop, they are going to need energy, and lots of it. Currently, the whole of Africa generates less electricity than Spain, and half of that is produced and used in South Africa. Only one third of homes in Africa have an electricity supply.

This new energy will increasingly be low carbon, firstly because of the national policies and cost issues discussed above, but also because international climate funds will be preferentially investing in low-carbon energy and because renewable energy really is the best option for many areas of Africa where there are no electricity grids – why build an expensive national grid when local generation and micro-grids are the cheaper option?

While baseload supply at night when the sun isn’t shining has often been cited as a need for continued reliance on coal, this is no longer strictly true. Baseload can be provided by other renewables, such as large hydropower and wind, coupled with new developments in night-time storage. Similarly, battery storage is becoming very competitive for micro-grids. For cities, grid-based electricity supply is probably still the best option, but this can also be supplied by renewable sources. Imagine the South African Renewable Energy Independent Power Producer Procurement Programme (REIPPPP) scaled across all of Africa!

If one looks beyond energy at the wider economy, there are many climate-sensitive sectors and businesses that may be at risk from global warming, but that can be made more resilient and productive by incorporating climate risks into their strategies.

Agriculture, food and fibre will be one of the main sectors most affected by climate, as productivity is closely tied to climate via heat and water availability. More widely, any activity that is dependent on water, for example mining, urban development, energy, beverages, or horticulture, may be impacted by climate change through changes in the reliability of water supply.

Climate change becomes particularly important for long-term investment decisions. On shorter timescales, less than 10 years, perhaps even 20, climate change will be a gradually emerging factor, superimposed on pre-existing climate risks. Apple farmers will still be able to grow apples in the Western Cape, and coffee producers will still be able to grow coffee in Kenya. But what about a coffee farm in 25 years’ time? Climatic suitability might well have shifted, so existing areas will be less productive, and investments should target coffee production in new areas that will be suitable in the future rather than now. In 40 years’ time sea levels might have risen by one third of a meter, coastal erosion might be accelerating, so where should new settlements in the coastal zone be located?

Screening long-term investment opportunities for climate risks, and thinking how climate change might alter the risk-return landscape is simply good practice. Many companies and investment agencies do this as a matter of routine already: the World Bank, the African Development Bank, SAB-Miller are all doing it; why not you?


CDKN (2015). The IPCC’s Fifth Assessment Report: What’s in it for Africa?

Africa Progress Panel (2015). Power, People, Planet: Seizing Africa’s Energy and Climate Opportunities. Africa Progress Report, 2015.

[http://www.africaprogresspanel.org/publications/policypapers/ 2015-africa-progress-report]

National Business Initiative (2015). Climate change, Water and the Green Economy.


SABMiller and WWF (2014). The water-food-energy nexus: Insights into resilient development. [http://goo.gl/yc44K7]


The 22nd session of the United Nations Conference of the Parties (COP 22) will be held on 7-18 November 2016 in Marrakech, Morocco. In anticipation of this meeting, we recap on last year’s session in Paris.

For the first time, a global climate deal was reached - the world is united to cut the carbon pollution that’s driving climate change by moving beyond the dirty fossil fuels of the past to the cleaner, smarter energy options that can power our future without imperiling the planet.

This sends a clear message to markets: we’re moving to a low-carbon global economy where the future belongs to those who invest in ways to make our homes, cars and workplaces more efficient and to get more clean power from renewable sources like the wind and sun.

Source: United Nations Framework Convention on Climate Change, December 2015


Prof Mark New
Director: African Climate and Development Initiative, University of Cape Town


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