It’s a depressing thought that whatever we do about climate change, some impacts are already baked in. Emissions in the atmosphere now are enough to ensure a 1.5 degree Celsius temperature increase compared to pre-industrial times. That already means severe climate impacts like droughts, flooding, and ocean acidification.
But a 1.5 degree, or even 2 degree increase, is a lot better than a 4 degree one. That level would make civilization difficult for much of the planet, and leave many of the world’s poorest people in a state of arrested development. Here is how a new World Bank report puts it:
The consequences for development would be severe as crop yields decline, water resources change, diseases move into new ranges, and sea levels rise. The task of promoting human development, of ending poverty, increasing global prosperity, and reducing global inequality will be very challenging in a 2°C world, but in a 4°C world there is serious doubt whether this can be achieved at all.
And yet, a 4 degree increase is the path we’re on, according to the World Bank. It forecasts we’ll get there by the end of the century, perhaps earlier. In turn, it says Latin America and the Caribbean, Middle East and North Africa, and East Europe and Central Asia are all likely to be severely affected. For example, in Brazil, it predicts a 30% to 70% decline in yield for soybeans and up to 50% decline for wheat. The Mideast could see 20% to 50% decline in rainfall. In the graphic here, you can see how differences of degrees impact each region.
“The benefits of strong, early action on climate change, action that follows clean, low-carbon pathways and avoids locking in unsustainable growth strategies, far outweigh the costs,” the report says. It calls for carbon pricing (e.g. through taxation), the end of government subsidies for fossil fuels, and more investment in renewables. It says the worst is avoidable but only through quick action.