So much for tree rings as a temperature proxy.
Huge Canadian Tree Growth Study.
Our analyses of a new methodologically standardized tree-ring dataset covering Canada’s boreal forest provide insights into the growth responses of this ecosystem to climate change. Although revealing no overarching “growth enhancement” or “growth decline” in recent years, results do point to significant regional- and species-related trends in growth. The observed link between climate variation and growth variability revealed unique evidence of an intensification of the impacts of hydroclimatic variability on growth late in the 20th century, in parallel with the rapid rise of summer temperature.
Such response can be attributed to annual growth variability in these forests being mainly driven by negative sensitivity to summer temperature (warmer summers leading to less growth) and positive sensitivity to summer soil moisture (more moisture leading to more growth)
What a shocker. The climate cycles keep going up and down and so-called global warming” doesn’t change it
Predictions that a warmer climate will lead to more rain for some but longer droughts for others might be wrong, according to a study of 12 centuries worth of data.
The study, published today in science journal Nature, found there was no difference between 20th-century rainfall patterns and those in the pre-industrial era. The findings are at odds with earlier studies suggesting climate change causes dry areas to become drier and wet areas to become wetter.
Fredrik Ljungqvist and colleagues at Stockholm University analysed previously published records of rain, drought, tree rings, marine sediment and ice cores, each spanning at least the past millennium across the northern hemisphere.
They found that the ninth to 11th and the 20th centuries were comparatively wet and the 12th to 19th centuries were drier, a finding that generally accords with earlier model simulations covering the years 850 to 2005.
However, their reconstruction “does not support the tendency in simulations of the 20th century for wet regions to get wetter and dry regions to get drier in a warmer climate”.
“Our reconstruction reveals that prominent seesaw patterns of alternating moisture regimes observed in instrumental data across the Mediterranean, western USA and China have operated consistently over the past 12 centuries,” the paper says.
Update: I had 2013 in the title. Sorry. (thanks justsoeguy31167)
According to the NOAA, California averaged 3.43 inches of rain in February 2014, which was only .42 inches below the 1901-2000 mean.
That is about 5.7X as much rain compared to January when California only averaged only .6 inches of rain.
One month of average rainfall won’t end a drought, but it sure helps.