When world leaders adopted the Paris Agreement in 2015, they invited the Intergovernmental Panel on Climate Change (IPCC) to prepare a report focused on the 1.5º C temperature target.
The IPCC Special Report on Global Warming of 1.5 Degrees is the response to that invitation.
Its conclusions took the many by surprise.
The best climate science needs to be effectively communicated to trigger climate action.
Here are its key messages explained in a simple way.
But global warming is accelerating.
CO2 emissions, main driver of climate change, are still increasing.
Global CO2 emissions from fossil fuel and industrial processes account for about 65% of global greenhouse gas (GHG) emissions. An additional 10% of global CO2 emissions are from land-use changes.
Since 2010, CO2 emissions from fossil fuel and industrial processes increased by 10%. In 2017, the increase was 2%.
CO2 emissions from fossil fuel and industrial processes increased by 10% since 2010.
In addition, CO2 emissions should reach net zero around 2050.
To achieve such drastic reduction in CO2emissions, the transition towards changing energy production should be expedited in the next decade.
The SR15 analyzed four options (or pathways) to generate energy in a different way while radically reducing CO2 emissions: low energy demand, fossil fuel development, sustainability and middle of the road.
For the Middle of the Road pathway, two complementary actions should be implemented by 2030:
CCS is one of the various additional CO2 removal measures and technologies that will also have to be implemented to stay below 1.5ºC. Others are afforestation and reforestation, land restoration and soil carbon sequestration, bioenergy with carbon capture and storage.
Because CO2 emissions have not been decreasing fast enough, CO2 removal measures and technologies will be critical to reach net zero CO2 emissions by 2050.
Some of these technologies, however, still require more research and development for the massive large-scale deployment required to stay below 1.5ºC.
Solar and wind energy has more than doubled since 2010. Despite this rapid expansion, a five-fold increase in solar and wind energy will be required by 2030.
Energy supply should not increase by 2030, but be kept at around 2010 levels.
This means that a much more efficient use of energy will be required to lower energy demand for an estimated global population of 8.7 billion people by 2030, particularly in electricity and fuel.
This is why: currently, annual global emissions of all greenhouse gases (GHG) are 52 GtCO2-eq.
To stay below 1.5ºC, global GHG emissions should be, on average, 27 (25-30) GtCO2-eq in 2030.
Even if all pledges are fully implemented, global GHG emissions are projected to be, on average, 54 (50-58) GtCO2-eq in 2030.
While the rapid transition required to stay below 1.5ºC is implemented, the impacts of climate change will continue.
Weather events are the result of natural factors. Weather events are also influenced by human-induced climate change.
Climate change has altered the intensity and frequency of weather events: heat waves, droughts, wildfires, as well as severe storms and hurricanes, both of which lead to flooding.
The number of weather events influenced by climate change have doubled, compared to the last decade, when global temperature was 0.4ºC below the current 1.1ºC above preindustrial times.
In a 1.5ºC world, weather events influenced by human-induced climate change would double again, negatively impacting human health, livelihoods, food production, water, and economic growth.
Governments, cities and private sector companies are continuing to make pledges to combat climate change.
Pledges are an important first step. Rapid implementation is now critical.
Climate action has to double.