Surface air temperature change is a primary measure of global climate change. The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85°C (90% CI: [0.65 to 1.06]), over the period 1880 to 2012 (IPCC, 2013). The effects of increased global surface temperatures, and the associated changes in climate include:
- Increases in the frequency and intensity of intense precipitation (Min et al., 2011), and increases in the proportion of the global land surface in extreme drought (Burke et al., 2006),
- Global sea level rise (Vermeer and Rahmstorf), which in turn may result in the erosion of beaches and coastal wetlands, increased flooding, and intrusion of saltwater into rivers, bays, and aquifers (Titus, 2008), and global ocean warming and acidification (Pörtner, 2008),
- Adverse effects to human health, due to thermal stress, and the increased prevalence of infectious diseases (McMichael et al., 2006), and increased food security risk (Zhao et al., 2017; FAO, 2008),
- Loss of terrestrial biodiversity at all system levels, including species-level reductions in range size and abundance, especially amongst endemic species (Warren et al., 2013).
According to GISS Surface Temperature Analysis data, over the 2008 to 2018 period, the mean surface air temperature was 0.76°C higher relative to the 1951 to 1980 baseline. 2016 was the hottest recorded year with the mean surface temperature being 1.02°C higher than that over the same baseline.
According to Vox's Sigal Samuel:
Thanks to new data from the Copernicus Climate Change Service, we now know that 2019 was the second-hottest year ever recorded. Only 2016 was hotter, and by a really infinitesimal amount, due to El Niño.
Weather events such as El Niño always have the potential to produce small fluctuations in global temperature trends, so I’m not going to go above a 60 percent estimated probability here. But I will say this: Overall, temperature has clearly been trending upward. And there is a solid likelihood that 2020 will be a hotter year for the world than 2019.
Will the average world temperature in 2020 be higher than in 2019?
This question resolves positively if the Global Annual Mean Surface Air Temperature in 2020 is higher than it was in 2019, according to NASA's GISTEMP data.
GISTEMP v4 data may be accessed here. Data can also be found here. Please make a copy by clicking "file" and then "make a copy" if you wish to edit it. If you make useful additions to the dataset, please share the file in the comments.