Words by TONY WHITEHEAD
The global temperature is definitely rising — but how do we prepare for a future that is both entirely certain and completely unknowable?
Species often evolve most quickly when under stress: a change in the environment forces adaptive improvements and only the fittest survive. Much the same could be said for the built environment. Design imperatives ushered in by the threat of global climate change have driven rapid advances in quality, so in many parts of the world buildings are now more airtight, better insulated, better cooled, less wasteful of materials and generally more efficient than ever before. Had the need to reduce carbon dioxide (CO2) emissions not existed, it might have been useful, as a design challenge, to have invented it.
But this is only the first phase of what is proving to be a quantum leap in building design. Climate change is already occurring and it will continue to happen over the coming century and beyond. It is not enough that building construction and operation should attempt to mitigate CO2 production: the built environment must also adapt to survive the new climate, and allow society to thrive in whatever conditions prevail.
We do, of course, have a general idea of what to prepare for. As summarized in the fifth assessment report from the UN Intergovernmental Panel on Climate Change (IPCC), “In urban areas climate change is projected to increase risks for people, assets, economies and ecosystems, including risks from heat stress, storms and extreme precipitation, inland and coastal flooding, landslides, air pollution, drought, water scarcity, sea level rise and storm surges.” This statement was communicated with “very high confidence” — the highest level of certainty employed by the IPCC.
The average global temperature is now 1°C higher than in the pre-industrial era, and we are already witnessing the consequences in the form of more extreme weather, rising sea levels and diminishing Arctic sea ice. In 2015, world leaders from 196 countries signed the Paris Agreement, committing to keep the temperature increase to “well below” 2°C and to working towards a lower threshold of 1.5°C. As they prepare to reconvene in December 2018, the IPCC has published its most strongly worded report yet, urging that 1.5°C should be seen as the maximum and outlining the significantly greater risks to people and the natural environment that would accompany a 2°C rise. The difference made by half a degree came as a “revelation” to the 91 authors of the report, who reviewed more than 6,000 studies.
According to the IPCC, there are just 12 years left to limit catastrophic climate change. But even if this very ambitious target is met, it still means the average global temperature will be half a degree higher than it is today. This represents a vast amount of extra energy in the world’s weather systems, resulting in a formidable range of negative impacts.
If the target is missed — and many experts now regard a 2°C rise as all but inevitable — the consequences for life as we know it will be severe. US-based research organization Climate Central forecasts that with a 2°C rise, homes occupied by 160 million people globally would be inundated by sea level rises, while a 4°C rise would result in the displacement of 600 million people, equivalent to the entire population of North America.
The future looks uncertain — doubly so given that the many and varied effects of climate change will impact on different areas of the globe in different ways. Furthermore, there is little agreement on when various future scenarios may come to pass. Having already been proven inaccurate by the passage of time, forecasters have stepped back from predicting changes by a certain date and instead tend to focus on what will happen when a certain temperature level is breached.