Thread by @Peters_Glen

THREAD

The global mean temperature for 2019 was 1.1±0.1°C above pre-industrial levels.
* 2019 is likely to have been the 2nd warmest in instrumental records
* The past five years are the five warmest on record

The @WMO State of the Climate 2019 is out:
trello.com/b/ZRR6ULx9/emb…

2. Global atmospheric concentrations of GHGs reached record levels in 2018
* CO₂ at 407.8±0.1 ppm, 147% above pre-industrial
* CH₄ at 1869±2 ppb, 258% above pre-industrial
* N₂O at 331.1±0.1 ppb, 123% above pre-industrial

3. In the 2009–2018 decade, both atmospheric CO₂ concentration & its growth rate increased, & land & ocean CO₂ sinks continued to grow in response to the rise in atmospheric CO₂ concentrations.

The land & ocean CO₂ sinks remove about 45% of all anthropogenic CO₂ emissions.

4. 2019 saw low sea-ice extent in both the Arctic &
Antarctic
* The daily Arctic sea-ice extent minimum in September 2019 was the second lowest in the satellite record
* In Antarctica, variability has been high with the long-term increase offset by a large drop in extent in 2016

5. The ocean absorbs around 90% of the heat that is trapped in the Earth system by rising concentrations
of GHGs.

Ocean Heat Content (OHC), which is a measure of this heat accumulation, reached record high levels again in 2019.

6. Over 2009–2018, the ocean absorbed ~23% of the annual CO₂ emissions, lessening the increase in atmospheric concentrations.

CO₂ absorbed in sea water decreases its pH, the last 20-30 years show a clear decrease in average pH at a rate of 0.017–0.027 pH units per decade.

7. As the ocean warms it expands & sea levels rise. This rise is further increased by the melting of ice on land, which then flows into the sea.

In 2019 the global mean sea level reached its highest value since the beginning of the high-precision altimetry record (January 1993).

Read more from the @WMO on the Statement on the State of the Global Climate 2019 & the urgent need for #ClimateAction in latest #StateofClimate report: bit.ly/38DKFwk

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