Agriculture and Climate Change: Strategies for Mi7ga7on and Adapta7on

Transcription

1 Agriculture and Climate Change: Strategies for Mi7ga7on and Adapta7on

2 What we know Atmospheric nitrous oxide methane

3 Globally Higher maximum temps More hot summer days Higher minimum temps Fewer frost days More heavy 1- day precip More heat waves Fewer cold waves More drought More wet spells More intense El Nino events More common El Nino events Observed (20th century) Very likely Likely Virtually certain Virtually certain Likely Possible Very likely Unlikely Likely Possible Likely Modeling (21st century) Very likely Very Likely Very Likely Likely Very Likely Very Likely Very likely Very Likely Likely Possible Likely Easterling et al. Science 289:

4 Regionally.. Increasing temperatures, par7cularly nighzme minima Precipita7on increasing Increasing incidence of high dew points Extreme rain events more frequent than early 20 th century, but comparable to late 19 th century. For an extended discussion of observed regional climate trends see h]p://climate.umn.edu/climatechange/climatechangeobservednu.htm

5 Soil Temperatures, St. Paul J.M. Baker & D.G. Baker Clima7c Change 54:

6 1200 Annual Precipita7on, Root River Basin 1100 basin average precip, mm

7 Stream Flow, Upper Mississippi at McGregor, IA

8 So, higher CO 2, more precipita7on, warmer temperatures, longer growing season. Why is this a problem for Minnesota agriculture?

9 Disease and Insect Pressures? Higher dew points Warmer night 7me temperatures Shorter, warmer winters

10 Weeds Among invasive species however, the response to recent increase in atmospheric carbon dioxide is striking, rising by almost 90% on average, with field bindweed, Canada thistle and perennial sowthistle showing strong responses (Table 2). Although only a limited number of studies involving the response to recent [CO2] increases are available, the response of noxious invasive species is about three 7mes that of the reported average for other plant species over this range of CO2 concentra7ons. L.H. Ziska & K. George World Resour. Rev. 16:

11 Likely impacts on agriculture Li]le change in ET Water Use Efficiency probable in yields due to longer growing season & CO2 threat of flooding heat stress on animals (and humans) due to temps, dew points disease pressure, maybe weed pressure threat of erosion threat to water quality ( precip, runoff, soil respira7on)

12 Adapta7on/Mi7ga7on Strategies: factors to consider Essen7ally all farming takes place on private property In the current economic and poli7cal climate, public funds will be scarce Time is of the essence

13 Mi7ga7on - Carbon Sequestra7on Ecosystem Range of CO 2 Sequestra;on Rates (metric tons C/acre/yr) Cropland 0.2 to 0.6 [0.5] Grassland / Prairie 0.1 to 1.0 [0.8] Forest 0.05 to 4.0 [1.2] Swamp / Floodplain / Wetland 2.2 to 3.7 [3.0] In agricultural systems the rates are not large, and are difficult to verify.

14 Mi7ga7on - Sustainable Displacement of Fossil Fuels Pyrolysis, methane genera7on, (not just liquid fuels) Emphasize products and processes that complement rather than compete with food produc7on Sustainable both economically and environmentally

15 Biochar Solid residue remaining ater the hea7ng of organic materials without oxygen Pyrolysis Easily degradable (0-5 yrs) Energy Recalcitrant carbon form (charcoal) (>50 to 1,000,000 yrs?)

16 Mi7ga7on- Increase N Use Efficiency = In terms of global warming poten7al, 1 N 2 O molecule = 300 CO 2 molecules

17 N 2 O Excessive or un7mely fer7lizer applica7on NO 3

18 Adapta7on - Increase landscape water storage capacity

19 Adapta7on- Diversify the landscape Increases resilience Lessens the likelihood and severity of disease and pest outbreaks Slows the development of resistant pathogens and weeds

20 Adapta7on - technology Wise use of new genomics tools Be]er integra7on of weather & climate forecasts in management & decision- making

21 Plan for climate change in the next farm bill Provide incen7ves (or remove disincen7ves) for mi7ga7on and adapta7on prac7ces