Urbanisation as an amplifier
AR6 reminds us that with dark impermeable surfaces our cities act to amplify many aspects of climate change. As the global population continues to rapidly urbanise, our cities become denser and we remove urban canopy cover, parks, cool green zones, floodplains and groundwater infiltration sites. These are the often-undervalued urban natural capital assets which all act to counter the effects of climate change.
In the Australian context the most deadly impact of climate change is the increasing severity and frequency of heatwaves. The impacts of these events are further amplified by the well known urban heat island effect. Urbanisation also increases mean and heavy precipitation over and downwind of cities which results in increased runoff intensity and impacts from flash flooding. In coastal cities, the combination of more frequent extreme sea level events (due to sea level rise and storm surge) and extreme rainfall/riverflow events will make flooding much more probable.
People can still make a positive change
Climate model projections show that the uncertainties in atmospheric CO2 concentrations by 2100 are dominated by the differences between our anthropogenic emissions scenarios. The rate and severity of future climate change is therefore still entirely under our control. The transition to a decarbonised economy is already underway and must be accelerated if we are to avoid the worst impacts of climate change in the coming decades.
The choice of societal responses to future climate change impacts will act to either increase or decrease community resilience to subsequent extreme events. Smart building design, holistic planning and low cost risk treatments can act together to effectively buffer our communities from climate impacts and markedly increase our resilience. Employing nature based solutions also provides us with an opportunity to sequester carbon while also protecting communities and assets from many climatic hazards.
The continued need to act
AR6 provides the strongest evidence yet of the continuing changes being experienced in the Earth’s climate. Given the increasing focus on climate risk disclosure, especially for government agencies and large corporate entities, the results of this new modelling need to be incorporated into current and future risk assessment to provide a better understanding of the challenges we face – and where to invest in building resilience. This is especially the case for organisations wanting to show leadership in how they assess and respond to climate change. AR6 also serves as a strong reminder of the need to rapidly decarbonise the global economy and why global gatherings such as the recent COP26 are essential for coordinated global action to reduce emissions.