Comments on the last post speculated that rainfall in Australia might show a trend if one looked at smaller regions than the entire continent. In particular, some wondered about the history of precipitation in New South Wales (NSW, one of the areas hardest hit by bushfires), and one reader was kind enough to point to data from Australia’s BoM (Bureau of Meteorology), featuring this map of the trends in rainfall since 1970 throughout NSW:
Almost every part of the state shows a declining trend. But how significant is the trend?
The bushfire season in Australia has been horrific. More horrific than any before. Axios offers a glimpse of what people are going through, while Metro reports that it has affected wildlife too — wildfires killing almost half a billion animals. Yes, I said billion.
Willis Eschenbach is wrong on both counts when he announces at the WUWT blog that “… according to NOAA, there’s been no increase in either droughts or wet periods in the US since 1895 …”
.@GretaThunberg, don’t let anyone dim your light. Like the girls I’ve met in Vietnam and all over the world, you have so much to offer us all. Ignore the doubters and know that millions of people are cheering you on.
— Michelle Obama (@MichelleObama) December 13, 2019
At the risk of repeating myself, I’ll repeat myself. Global temperature is a combination of trend and fluctuation.
The fluctuations make it jitter about from year to year (or month to month, or day to day, or whatever), but the trend of late has been steadily upward. It’s called global warming (although some might prefer “global un-cooling”). We even know some (but not all!) of the causes of the fluctuations; things like the el Niño southern oscillation (ENSO), massive volcanic eruptions, and variations in the output of the sun itself. But the fluctuations don’t last. The trend, however, continues upward unabated.
Earth’s hottest year on record remains 2016, when the warming from man-made climate change combined with extra heat from the strong el Niño of that year. But even without el Niño, this year is likely to come in a strong 2nd. Here are yearly averages since 1950 from NASA, with the 2019 value year-to-date (January through October):
We have several estimates of global sea level based on tide gauge data, and I’d like to compare four of them. First is the best-known and probably most trusted, from Church & White, which I’ll call CW. Next is one I’ve heavily criticized in the past, from Jevrejeva et al., I’ll call it Jev. We also have a recent new approach from Dangendorf et al. which I’ll refer to as Dang. Last (and least) is my own reconstruction (Fos) using my method to align station records and account for VLM (vertical land movement).
I aligned them all to have the same baseline (from 1993 to mid-2010 so I could also put satellite data on the same baseline). First I’ll graph for you their yearly averages, and we notice right away that Jev and Fos start way back in 1807, while CW delays until 1880 and Dang doesn’t begin until 1900: