Recent interactions with some of the South African contributors to the latest Intergovernmental Panel on Climate Change (IPCC) working-group reports highlighted the increasing complexity of future investment choices, particularly in the energy milieu.

For one, adaptation is likely to emerge as a key theme, particularly in light of measurements showing that global greenhouse-gas emissions not only rose to unprecedented levels, but also grew more quickly between 2000 and 2010 than in each of the three previous decades.

In other words, it is now doubtful that mitigation actions – which the IPCC scientists still insist remain pivotal – will be sufficient to avoid the 2 °C temperature rise above preindustrial levels viewed as a key tipping point. In fact, the Working Group III report warns that without more mitigation, the global mean surface temperature might increase by up to 4.8 °C over the current century.

As a consequence, investors, especially infrastructure investors, are likely to be compelled to become increasingly mindful of the long- term economic costs posed by climate change. As one lead author of a chapter in the IPCC’s Working Group III contribution to the Fifth Assessment Report puts it: a least-cost decision-making framework will increasingly have to be balanced with climate considerations.

In fact, University of Cape Town Energy Research Centre director Professor Harald Winkler believes that investors will be expected to weigh multiple goals when, for example, choosing between coal, nuclear and renewable-energy projects.

Winkler says investors will be asked to pay closer attention to the emerging reality of a “carbon constrained world”, as a failure to do so could carry serious direct and indirect economic costs. “We can’t just say we will take the least-cost option. Cost is still a conside- ration, of course, but addressing poverty is critical and investments must also address climate change. We need solutions that can do all three – that’s the challenge and it’s a big challenge.”

But adaptation is not the only challenge, as Council for Scientific and Industrial Research systems ecologist Dr Bob Scholes cautions. He warns that adaptation strategies will have limitations and should be coupled with early and aggressive mitigation actions to deal with both the increase and the rate of increase in the change in climate. The rate of climate change, he presages, is many times faster than the fastest changes in climate that have occurred over the last million years.

“Humans like to think of ourselves as the smartest species on the planet – we even named ourselves ‘homo sapiens’ – the knowledge- able ape. It’s quite ironic, therefore, that plants and animals are not having a debate about whether climate change is occurring or what to do about it – they are voting with their feet. They are changing their behaviours. They are migrating towards the poles. The problem is that they can’t do it fast enough.”