The Intergovernmental Panel on Climate Change (IPPC) published a new report on Monday Aug. 9.
- The report shows temperatures rising more quickly than expected and show the long-term effects of increased CO2 in the air.
- Public and private actors must act now to get to net zero.
Baseline temperature refers to the predicted increase in average global temperature rises. Earlier in the year, the UK Met Office and World Meteorological Organization released research demonstrating that there is more than a 40% chance that the annual average global temperature in at least one of the next five years will temporarily reach 1.5C above pre-industrial levels. Through the Paris Agreement in 2015, the international community agreed to keep global temperature rise this century well below 2.0°C degrees above pre-industrial levels, and to pursue efforts to limit temperature increase to 1.5°C. The 1.5°C threshold is important because beyond this, so-called “tipping points” – positive feedback loops where global warming causes a permanent shift in earth systems, locking in further warming – become more likely.
The IPCC climate change report brings forward when scientists expect to reach 1.5C to the mid-2030s, at which point tipping points such as lose of artic sea ice, larger-scale die-offs of coral reefs, and thawing of the methane-rich permafrost become much more likely.
Another core concept in the IPCC report about climate change is the long-term effect of increased CO2 in the air. The Earth takes time to adjust to increases of CO2 in the air, and the Equilibrium Climate Sensitivity (ECS) estimates how much the earth will warm with a doubling of the amount of CO2 in the air. This is important because CO2 has increased from its pre-industrial level of around 280 parts per million (ppm) to an estimated 415 ppm today, with a predicted doubling of CO2 in the air around 2060.
Recent research predicts the increase in global average temperature with a doubling of CO2 in the air to between 2.6-4.5C. The difference between 1.5C short term, and between 2.6C and 4.5C longer term may seem small at first glance. However, the difference between 1.5C, 2C, and 3C is the difference between average droughts lasting two, four or 10 months per year, and the difference between 6%, 18% or 68% (for an increase to 4.5C) means invertebrates globally losing their habitat. These longer-term trends are in addition to the current extreme weather we are witnessing across Europe and the US today.
In Ireland, there will be significant impacts on our water resources. There will be more intense storm and rainfall events resulting in flooding, coastal erosion and coastal flooding and drier summers resulting in water shortages in some areas.
The cost of doing nothing will be much greater than taking preventative action now. If the right policies are put in place and action is taken now it is still possible to prevent reaching tipping-points and runaway global warming. Reducing global CO2 emissions to net-zero between now and 2050, will put us in line with a 50% chance of staying within 1.5 degrees of warming by 2100, according to the Intergovernmental Panel on Climate Change (IPCC).
Most of the technologies for a net-zero energy system are available today and while technology cost must be reduced further and deployment can be accelerated through innovations, we need to start now. Fossil fuel use must decline by 75% by 2050 with natural gas accounting for the remaining fossil fuel use according to a report by the International Renewable Energy Agency.
The report states that the transition is affordable. Total energy sector investments increase from $98 trillion in the Planned Energy Scenario (PES) under current plans and planned policies to $131 trillion in the 1.5C scenario, a 34% growth. To put that number in perspective, global GDP amounted to $81 trillion in 2019 and GDP is projected to increase 2.5-fold by 2050.
We cannot say we did not know but it will take political will to drive the necessary changes.