From ecoRI News (ecori.org)
Stop me if you’ve heard this story before: Last month was the warmest ever.
The latest global temperature data show that November 2020 was the warmest November ever recorded. The above figure shows the overall trend in global temperatures since 1880.
The red line for 2020 shows that average temperature for November was significantly above that of previous years. The significant rise in November’s temperature makes it very likely that 2020 will be the warmest year on record.
The figure below shows the average global November temperatures since 1880. The rise in November temperatures is quite substantial. The figure also shows that recent November temperature rises have been even more dramatic.
November mean surface air temperatures over land and ocean every decade since 1880. Data source: NASA GISTEMP. (Roger Warburton/ecoRI News)
In fact, the rise in November temperatures since 2015 is in line with a particularly disturbing trend: The latest data show that, since 2015, the warming trend is accelerating. The figure below shows the seriousness of the problem.
Global air temperatures over land and ocean. The yearly mean, blue, and the 5-year mean, red, have risen significantly above the gray trend line. Data source: NASA GISTEMP. (Roger Warburton/ecoRI News)
The gray line represents the steadily rising global temperature that was reasonably steady between 1970 and 2015. Since then, the temperature rise has accelerated. This is shown in the figure by the blue and red curves rising significantly above the gray trend line.
The gray trend line has often been used to predict long-term impacts of the future temperature rise. If the acceleration continues, many of the current estimates of the impacts of global warming will be seen as severely underestimated.
Roger Warburton, Ph.D., is a Newport resident. He can be reached at rdh.warburton@gmail.com.
References: GISTEMP Team, 2020: GISS Surface Temperature Analysis (GISTEMP), version 4. NASA Goddard Institute for Space Studies. Dataset accessed 20YY-MM-DD at https://data.giss.nasa.gov/gistemp/. Lenssen, N., G. Schmidt, J. Hansen, M. Menne, A. Persin, R. Ruedy, and D. Zyss, 2019: Improvements in the GISTEMP uncertainty model. J. Geophys. Res. Atmos., 124, no. 12, 6307-6326, doi:10.1029/2018JD029522.
