This document discusses increasing drought trends in the Northern Hemisphere from 1950 to 2009. It summarizes research showing that drought has increased in the NH, particularly affecting important food producing regions. The drought increase is linked to rising global temperatures which reduce snow and ice cover in the Arctic and on Greenland, lowering their albedo and ability to reflect sunlight and cool the climate. Record losses of Arctic sea ice, Greenland ice sheet area, and spring snow cover were observed in 2012, potentially exacerbating drought trends through this albedo and climate feedback mechanism.

1. Drought trends
Dr. Peter Carter

2. Drought trends
USA 2012

3. Global average temperature increase

4. All the worlds best food producing regions are
in the Northern hemisphere
Any effect on NH food production increases world food prices severely
increasing the Global South’s food insecurity.

5. Increasing global drought 1950-2009
Drought Palmer Drought
under global Severity Index
PDSI
warming:
a review
Aiguo Dai
Wiley Jan 2011
FIGURE 11 | Mean annual sc-PDSI pm for years (a) 1950–1959, (b) 1975–1984, (c) 2000–2009,
(using the 22-model ensemble-mean surface air temperature, precipitation, humidity, net
radiation, and wind speed used in

6. Increasing global drought
affects most of the worlds best producing regions
Palmer Drought
Severity Index
PDSI
Drought under global warming: a review Aiguo Dai Wiley Jan 2011
FIGURE 11 | Mean annual sc-PDSI pm for years (a) 1950–1959, (b) 1975–1984, (c) 2000–2009,
(using the 22-model ensemble-mean surface air temperature, precipitation, humidity, net
radiation, and wind speed used in the IPCC AR4 from the 20th century

7. Increasing regional Northern hemisphere drought
1950-2009
Palmer Drought
Severity Index
PDSI
Drought under global warming: a review Aiguo Dai Wiley Jan 2011
FIGURE 11 | Mean annual sc-PDSI pm for years (a) 1950–1959, (b) 1975–1984, (c) 2000–2009, (using the 22-model ensemble-mean surface air temperature, precipitation,
humidity, net radiation, and wind speed used in the IPCC AR4 from the 20th century

8. http://drought.mssl.ucl.ac.uk/drought.html
Palmer Drought
Severity index

9. Palmer Drought
Severity index

10. Palmer Drought
Severity index

11. 12 months
UCL algorithm

12. Northern hemisphere
12 months
UCL algorithm

13. 12 months
UCL algorithm

14. 12 months
UCL algorithm

15. NASA GISS

16. NH
SH
Average temp increase
NASA GISS

17. Decadal Northern hemisphere warming trend

18. Perception of climate change
James Hansena,1,
Contributed by James Hansen, March 29, 2012
With global warming NH summer heat extremes are increasing.

19. 2012 to September NOAA
http://www.ncdc.noaa.gov/sotc/global/

20. 2012 to September NOAA
http://www.ncdc.noaa.gov/sotc/global/

21. Rapid 2012 record loss of Arctic albedo cooling
Rapid loss of Far North and Arctic snow and ice albedo cooling could be expected to
increase NH drought. Research indicates the jet stream is being altered with a
tendency to prolonging droughts.

22. June 2012 record loss of Arctic snow cover albedo cooling
Northern Hemisphere
Visible Satellite
Monthly Departure
(from 1971-2000
mean)
It is thought that the
faster retreat of the
spring-summer far North
snow cover is a big part
of increasing NH drought.
Variation from the post-
1967 historical norm in
June snow cover, June
2012. Dark orange
corresponds to between
75 and 100 percent
below average. Image:
From Rutgers University
Climate Lab

23. July 2012 record Greenland ice surface loss of albedo cooling
Melt water covering the Greenland ice surface lowers albedo
Less albedo
reflection
cooling
http://bprc.osu.edu/wiki/Greenland_Ice_Albedo_Monitoring

24. 2012 record loss of Arctic sea ice albedo and
record loss of Greenland albedo cooling