Ahead of the United Nations Climate Action Summit in New York this week, the World Meteorological Organization (WMO) has released a new climate report titled United in Science, detailing the current state of the climate. Focusing on the last five years, the report shows that these have been the hottest years on record, and highlights how far off track we are from meeting the goals of the Paris Agreement.
Put together to inform those world leaders attending the UN Climate Action Summit this week, the new report essentially compiles data from several previous reports into one place. It has a particular focus on 2015 to July 2019, showing an increase in broken heat records, greenhouse gas emissions, and the tell-tale signs of climate change, such as sea level rise, ice loss and extreme weather events.
Collectively, the last five years are the hottest since records began in 1880, while the top 20 all fall within the last 22 years. It may not yet be over, but 2019 is on track to join the ranks, with July this year found to be the hottest month ever recorded.
The global average temperature between the years 2015 and 2019 was found to be 1.1° C (2° F) higher than the average in the pre-industrial period. Even compared to the previous five-year period of 2011 to 2015, it’s up by 0.2° C (0.4° F).
These record-breaking temperatures may be the result of another broken record: that of greenhouse gases in the atmosphere. It was during this five-year period that levels of carbon dioxide in the atmosphere surpassed 400 parts per million (ppm), a level that hasn’t been seen on Earth for over three million years. Preliminary reports suggest that we’re on track to reach, or even surpass, 410 ppm by year’s end. It doesn’t help that CO2 growth rates increased by 20 percent compared to the previous five years.
All this carbon and heat is having tangible effects on the climate and environment. Extreme weather events are becoming more common, with heat waves affecting every continent and leading to many new local temperature records. Wildfires, hurricanes and cyclones have been increasing in intensity, with many new records in devastation and economic costs.
The record high temperatures are also causing record lows in terms of sea ice at the poles. The four lowest records for winter sea ice in the Arctic were in each of the four years from 2015 to 2018. Antarctica fared little better, with its two lowest summer sea ice records occurring in 2017 and 2018.
The speed at which Antarctic ice sheets are losing ice has increased six-fold, up from 40 gigatons a year between 1979 and 1990, to 252 gigatons between 2009 and 2017.
All this melting ice is raising sea levels faster too. The global mean sea-level rise was 5 mm per year between May 2014 to 2019, which is far faster than the average rate of 3.2 mm per year since 1993. These oceans are warmer and more acidic: this five-year period saw the top three ocean temperature highs, and an increase in acidity of 26 percent since the industrial revolution.
Similar trends were playing out when the Paris Agreement was signed way back in 2015, and the report also examines how on-track we are to meeting the targets laid out then. The outlook isn’t great. So far we’re on track to reduce global emissions of CO2 by the equivalent of 6 gigatons by 2030 – to limit warming to less than 2° C we need to triple that, and to hit the more ambitious goal of 1.5° C a fivefold increase over current efforts is required.
This new report is worrying (and worryingly familiar), but it should serve to focus international efforts at this week’s UN Climate Action Summit. Combined with the incredible turnouts for the climate strikes last Friday, it will hopefully inspire world leaders to act.
"This new assessment is another sobering reminder of the critical state of the climate crisis and a call on governments, businesses and civic society to act more determined and aggressively in reducing greenhouse gases emissions,” says Pep Canadell, chief research scientist at CSIRO and a contributing author on the report. “Nothing in this report should come as a surprise but a confirmation of the trends well established by the scientific community, with a distinctive acceleration of climate changes in the past three decades, and particularly in the most recent one. How many climate records does it take to accept the unprecedented nature of what we are living and to act upon it?”
The report was published online. A basic breakdown can be seen in the video below.
