Third National Climate

Assessment (2014)

Specialty agriculture in future climate:A personal view of the NCA

Richard GrotjahnUC Davis Professor and California Pistachio Farmer

Rich Fields Farm

California: Leading commodities for cash receipts, 2009

Percent Percent Value

Rank Items Value of of total Cumulative of U.S. of U.S.

indicates #1 state receipts receipts percent 1/ value 2/ receipts

indicates #2 state 1,000 dollars ------------ Percent ------------ 1,000 dollars

All commodities 34,840,647 100.0 -- 12.3 283,406,168

Livestock and products 7,814,006 22.4 -- 6.5 119,751,629

Crops 27,026,641 77.6 -- 16.5 163,654,539

1 Dairy products 4,537,171 13.0 13.0 18.6 24,342,440

2 Greenhouse/nursery 3,792,295 10.9 23.9 23.8 15,914,592

3 Grapes 3,267,848 9.4 33.3 88.6 3,689,412

4 Almonds 2,293,500 6.6 39.9 100.0 2,293,500

5 Lettuce 1,725,799 5.0 44.8 78.8 2,189,219

6 Strawberries 1,725,232 5.0 49.8 81.2 2,124,195

7 Cattle and calves 1,676,373 4.8 54.6 3.8 43,776,568

8 Tomatoes 1,509,647 4.3 58.9 59.4 2,541,986

9 Rice 928,173 2.7 61.6 30.5 3,041,344

10 Hay 864,163 2.5 64.1 15.1 5,726,526

11 Walnuts 738,530 2.1 66.2 100.0 738,530

12 Broccoli 698,376 2.0 68.2 94.1 741,900

13 Oranges 655,820 1.9 70.1 32.9 1,993,237

14 Pistachios 592,850 1.7 71.8 100.0 592,850

15 Carrots 499,766 1.4 73.2 84.9 588,942

16 Lemons 364,248 1.0 74.3 92.4 394,199

17 Celery 349,918 1.0 75.3 95.9 364,816

18 Peaches 326,331 0.9 76.2 54.9 594,248

19 Chicken eggs 319,771 0.9 77.1 5.2 6,155,825

20 Cotton 303,823 0.9 78.0 8.7 3,488,956

21 Raspberries 297,315 0.9 78.8 82.0 362,606

22 Cauliflower 255,766 0.7 79.6 89.2 286,612

23 Plums and prunes 251,923 0.7 80.3 97.6 258,043

24 Wheat 230,752 0.7 81.0 2.0 11,315,147

Calif.Ag. is #1

(Top 24 crops)

Red is 1st in USYellow is 2nd in US

CentralValley

irrigation

• farmers irrigate a lot in the central valley – that’s why its green surrounded by brown in this photo from space

Photo © NASA

Ag-climate factors

• Models predict warmer, drier periods that matter to Ag.

• A2 scenario• Frost free season• # frost days• Consec. dry days• # hot nights

On average everything hotter

• Many climate models predict warming of extreme temperatures. (RCP8.5 scenario)

• Winter min• Winter max• Summer min• Summer max

The ‘new wave’ is heat waves• 5 day heat wave becomes the median!

(RCP 8.5 scenario)• Longest periods off the chart: one is 36

another is 42 days in a row!

Source: Grotjahn (2013)

Source: Grotjahn (2013)

Irrigation is cool!

• Irrigation means evaporation and that makes it 3-5 F cooler.

Photo © NASA

Plants have AirConditioning!

• Plants AC is ‘transpiration’• Different plants respond

differently to heat. • Some don’t like it hot• For many, yields decline as T

goes up

Just add water

• Plants use water to transpire and not wilt

• First adaption is to pour on more water.

• Problem solved!

• Except…• more water from where?

Photo © EPA

Don’t look down for

water

• Groundwater levels declining

• Water may be way down, at historic depths

Sourc

e:

Calif

orn

ia D

WR

(2

01

4)

Don’t look up for more water

• Models predict, on average:

• winter precip. about same,

• spring may be drier

Calif. will be less (snow) flakey!

• Much less will be stored as snow

• Over all the SW

Dam! where’d the water go?• Dams don’t store as much. • And, now you see it, now you don’t• Droughts come and go, but people want to eat all the

time• July 2011 January 2014

Photo

s ©

USG

S

Just add water? … stress!

• Brown is not good

• And there are other climate-related stressors mentioned in the NCA

Photo

s ©

UC

AN

R

Some like it hot

• Many insect pests like the heat, • pathogens too, • some weeds grow better, • oh my!

• Time for one more extreme…

Did I mention, CA is #1?

• California is number 1 in peaches

• You didn’t think it was Georgia, did you???

Photo

© R

. G

rotj

ahn

CA crops need to chill out!

• Peaches and other stone fruits, pomme fruits, tree nuts, need a dormant period each winter measured in hours between freezing and 50F

Photos © UCANR or R. Grotjahn

Never enough time to do what you need to do (chill)

• Those chilling hours are declining,

What goes up (mostly) comes down(at least it used to)

• Weather is not climate, it has ups and downs.

• Ag can adapt to some variation

• Average summer max temperatures may be a standard deviation above today’s norm

Conclusions: Future Shock!

• Everything warmer• Extremes become the

norm.• California will be less

(snow) flakey• Want more water that’s

not there• Ag will adapt & change

For More Information:http://nca2014.globalchange.gov/

Chapter 6: Agriculture