The Intergovernmental Panel on Climate Change (IPCC) have released their most comprehensive report on the physical science of climate change to date. This report is the result of three years of work from more than 200 scientists across the world, and it sets the scene for the November UN climate summit in Glasgow. The report, at first glance, is pretty bleak. It paints a dire picture of the earth’s future if we do not act now.
The report considers how likely global warming of 1.5°C will be exceeded under five greenhouse gas (GHG) emission scenarios. This threshold is taken from the Paris Agreement, under which almost 200 nations agreed to pursue efforts to limit global warming to 1.5°C above pre-industrial levels.
These scenarios span very low to very high GHG emissions. The report found that global warming of 1.5°C is likely to be exceeded in the intermediate, high, and very high scenarios, and is more likely than not to be exceeded in the low emissions scenario.
To put this in context, limiting global warming to 1.5°C is associated with a 2 – 3m sea level rise whereas global warming of 5°C could result in a 19 – 22m sea level rise.
The report also found that both land and ocean carbon sinks become less effective as CO2 emissions increase. “Our oceans act as these incredible carbon sinks, absorbing more than half of the CO2 that the world emits,” says Gemma Coutts, OSOF policy coordinator. “This means that as CO2 emissions increase, a higher portion of CO2 remains in the atmosphere. Under higher emission scenarios these natural carbon sinks even turn into carbon sources and begin to emit CO2.”
Many of these consequences will continue to compound as emissions increase, and will eventually become irreversible.
“As this report highlights, if we continue ‘business as usual’, we will start to see irreversible damage to the environment. We’re already starting to see it – floods in Canterbury and the West Coast, fires in Australia. These are the results of climate change,” says Coutts.
Fortunately, it is not all doom and gloom. The report makes it clear that there is still time to limit global warming to 1.5°C by the end of this century if we take ambitious action to reduce our emissions.
“We need to reach net zero CO2 emissions and implement major cuts to other GHG emissions, including methane, as soon as possible,” says Coutts. “It’s clear that this is our make or break decade, and our last chance to prevent some of the most catastrophic effects associated with global warming.”
“Simple things like driving one less day to work, or carpooling can make a difference if we all do it,” says Coutts. “This is also the time to be holding our government accountable and to place more pressure on large corporations. They need to be transparent about how they will be committing to reducing CO2 emissions.”
“If lockdown taught us anything, it’s that we need nature and healthy, thriving environments for our own mental wellbeing. Achieving net zero will be hard, but the benefits will outweigh the challenges,” adds Coutts.