In short: All of this makes it politically and economically feasible to completely shift to zero carbon technologies over the coming two decades, not only in wealthy countries but also in the global south. It is now possible for developing countries to grow their economies, achieving other development objectives such as eliminating hunger and raising life expectancies, while also eliminating emissions.
Now is the time to act
There are many other messages: the new report looks at how our lifestyles impacts climate change, where emissions come from and how we can reduce them in areas such as energy, land, buildings and cities, and transport. The Summary for policymakers
alone runs to 40 pages, and the report itself over 1,000. If there is one overarching theme to emerge on which all authors agree, it is that now is the time to act.
Now is the time because the climate demands it. Unless global emissions start to fall quickly, to roughly half their 1990 values by 2030, we will miss the opportunity to hold global warming to 1.5°C, a critical value. Simply put, the positive changes we have seen so far are not enough. The rate of decline in emissions seen in some countries is not enough, and the decline needs to spread to all countries.
Now is also the time because the technological, economic, and to a large extent political, barriers have fallen. The emergence of win-win options I described above means that the economic costs to society of halving our emissions by 2030 and reaching net-zero emissions by 2050 – most importantly eliminating the use of fossil fuels – are trivially small. They may even be negative once we take immediate co-benefits into account, such as improved air quality.
To completely phase out all fossil-based systems by 2050, annual investments in zero-carbon systems, replacing the huge capital stock, have to more than double in wealthy countries, and rise by at least factor four in developing countries. This will require government policies geared to increasing the rate of investment. While many policies are in place, they too are limited. There is still a major gap between what countries are proposing to accomplish by 2030, and what is needed.
Keep up the pressure
Whether we will act, quickly enough, is a question this week’s WG III report cannot answer. Some industries, notably fossil fuels, will suffer or die, and there are powerful interests opposing that. Any change in government policy is challenging, requiring negotiation and compromise. I believe it is vital for well-informed people to keep up the pressure on our governments to act as decisively as possible. The biggest challenges lie ahead.