Compared to the previous five-year assessment period 2011–2015, the current five-year period 2015–2019 has seen a continued increase in carbon dioxide (CO2) emissions and an accelerated increase in the atmospheric concentration of major greenhouse gases (GHGs), with growth rates nearly 20% higher. The increase in the oceanic CO2 concentration has increased the ocean’s acidity. The five-year period 2015–20191 is likely to be the warmest of any equivalent period on record globally, with a 1.1 °C global temperature increase since the pre-industrial period and a 0.2 °C increase compared to the previous five-year period.

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