In #11 we looked at “droughts from rainfall”, i.e., rainfall deficits. There were regional variations but no obvious global trend. In fact, we expect more rainfall as the earth warms (warm air holds more moisture) so a question to return to in a later article is why there hasn’t been an obvious increase in rainfall, i.e., why there hasn’t been a reduction in “droughts from rainfalls”.
Somewhat off-topic comment - For farming, no-till practices allow for successful crops during drought periods. No till seed drills plant seeds directly through grass and weeds. The grass and weeds are then killed with selective herbicides that will not kill the GMO seeded crop. GMO has gotten a bad name by anti-GMO movements, but there are no studies that prove GMO crops or associated herbicides are harmful to people or animals. Of course that doesn't stop the 1-800-BAD-DRUG lawyers from going after deep pockets.
In #10 (Into to Drought), you wrote that there are three kinds of droughts:
1) [reduced] rainfall,
2) [reduced] soil moisture [due to decreased precipitation and increased transevaporation]
3) hydrological (which may be less water in reservoirs, rivers and ground water)
We can measure any reduction in precipitation, and there has probably been a trivial increase in precipitation because warmer air can hold more water. However, I believe you said we had no systematic way of monitoring changes in soil moisture. Above, Spinoni et al 2019 report the change drought in terms in terms of "drought events" per decade, which is not a very robust way to quantify something. More comprehensive monitoring alone can cause an increase in detected events. With limited ability to systematically measure soil moisture, our ability to count the number of times and places that cross the threshold for being counted as a "drought event" can't be very robust. Yield of crops per acre might be a more meaningful measure of the IMPACT of increasing drought AFTER MITIGATION. So might falling levels of ground water in wells. Does the IPCC discuss other metrics for drought.
We have the same problems with in homogeneity in the record of TCs "events". As our surveillance has improved, our count of the number of TCs qualifying as Category 1 hurricanes and Category 3 or 4 ("major" hurricanes) has improved. In Kossin's paper, homogenizing the hurricane record by downgrading the resolution of images to a common low-resolution at the beginning of the satellite period reduced the count of TCs and major TCs in the past two decades by about 30%. Crossing a threshold to be counted as a TC or major TC is less reliable method of quantifying TCs (IMO) than more continuous monitoring such as Accumulated Cyclone Energy. I suspect the same applies to quantifying droughts by "events".
I'm not sure how anyone can say soil moisture decreases are "bad news" and say they are related to warming, when it's been cooling for the last 8 years.
Somewhat off-topic comment - For farming, no-till practices allow for successful crops during drought periods. No till seed drills plant seeds directly through grass and weeds. The grass and weeds are then killed with selective herbicides that will not kill the GMO seeded crop. GMO has gotten a bad name by anti-GMO movements, but there are no studies that prove GMO crops or associated herbicides are harmful to people or animals. Of course that doesn't stop the 1-800-BAD-DRUG lawyers from going after deep pockets.
In #10 (Into to Drought), you wrote that there are three kinds of droughts:
1) [reduced] rainfall,
2) [reduced] soil moisture [due to decreased precipitation and increased transevaporation]
3) hydrological (which may be less water in reservoirs, rivers and ground water)
We can measure any reduction in precipitation, and there has probably been a trivial increase in precipitation because warmer air can hold more water. However, I believe you said we had no systematic way of monitoring changes in soil moisture. Above, Spinoni et al 2019 report the change drought in terms in terms of "drought events" per decade, which is not a very robust way to quantify something. More comprehensive monitoring alone can cause an increase in detected events. With limited ability to systematically measure soil moisture, our ability to count the number of times and places that cross the threshold for being counted as a "drought event" can't be very robust. Yield of crops per acre might be a more meaningful measure of the IMPACT of increasing drought AFTER MITIGATION. So might falling levels of ground water in wells. Does the IPCC discuss other metrics for drought.
We have the same problems with in homogeneity in the record of TCs "events". As our surveillance has improved, our count of the number of TCs qualifying as Category 1 hurricanes and Category 3 or 4 ("major" hurricanes) has improved. In Kossin's paper, homogenizing the hurricane record by downgrading the resolution of images to a common low-resolution at the beginning of the satellite period reduced the count of TCs and major TCs in the past two decades by about 30%. Crossing a threshold to be counted as a TC or major TC is less reliable method of quantifying TCs (IMO) than more continuous monitoring such as Accumulated Cyclone Energy. I suspect the same applies to quantifying droughts by "events".
I'm not sure how anyone can say soil moisture decreases are "bad news" and say they are related to warming, when it's been cooling for the last 8 years.