The Training on…“Organic Vegetable Production and Marketing”

By…. Assist. Prof., Dr. Tiwa Pakoktom

Topic…“Climate change and impact to agriculture”

1

A significant change in climate on a globalscale will impact agriculture and consequentlyaffect the world’s food supply.

Climate change per se is not necessarilyharmful; the problems arise from extreme eventsthat are difficult to predict.

(FAO, 2001)

What have you heard?

What have you heard?

Is Global Warming Fueling Katrina?

How one number touched off big climate-change fight at UW

Global warming could burn insurersActivists call on industry to act

Jellyfish creature the answer to global warming? www.Scienceblog.com

EXAGGERATED SCIENCE

How Global Warming Research is Creating a Climate of Fear

Research Links Global Warming to Wildfires In a Shift, White House Cites Global Warming as a Problem

Global warming causing new evolutionary patterns

Rise in wild fires a result of climate change

Seattle mayors' meeting a cozy climate for business

Seattle reports milestone in cutting emissions

Climate: refers to average weather over time and/or geographic area. (example: the average temperature in KPS in 2016 was …)

Weather: refers to what is happening at any giver time (example: today’s high temperature is…)

Potential influences on climate change:1) Sunspot activity

2) Volcanoes

3) Ocean current changes

4) Earth’s wobble or orbital

5) Atmosphere (greenhouse effect)

Sunspots!

No evidence of more volcanoes

Ocean circulation

The Great Ocean Conveyor

Sinking cool water, rising warm water and wind help to form global ocean current systems.

Sensitivity to Orbital Parameters

IPCC AR4 2007Milankovitch Theory

Could we believed?

WE NEED REAEARCH !

• Almost 1000 studies dealing with different aspects of climate change have been conducted and published

• So… how do we make sense of all this?

(IPCC)

Is the global surface temperature rising?

Data from IPCC

Global mean temperatures are rising faster with time

100 0.074±0.01850 0.128±0.026

Period Rate

Years °/decade

Loss of Sea Ice

PCC slide no. 038 Source: Arctic Council 2004

1979 2003

2010-2030 2040-2060 2070-2090

Sea-level from satellites: 4 cm rise in last 10 years

Melting Ice and Rising Sea Levels

1957

1998

Glacier retreat : Pasterze glacier site, Austria

1875 2004

Melting Ice : picture of Columbia Glacier, Alaska

Rising sea levels

Eroding coastlines

Rise in global ocean heat content 1955-2005

Some ups and downs, but clear overall increaseLevitus et al., 2005

Trend of yearly average temperature changing of Thailand (TRF)

Trend of yearly accumulate amount of rainfall changing of Thailand (TRF)

There are 3 phenomenon of solar radiation : - Transmittance- Absorption- Reflection

GHE#1 - natural

Earth’s Natural Greenhouse Effect

GHE#2 - humansHuman-caused Global Warming

Earth’s Atmospheric Gases

Nitrogen (N2)

Oxygen (O2)

Water (H2O)

Carbon Dioxide (CO2)

Methane (CH4)

Non-Greenhouse

Gases99%

GreenhouseGases

1%Nitrous Oxide (N2O)

Absorption Spectra of Atmospheric Gases

CH4

CO2

N2O

H2O

O2 & O3

atmosphere

WAVELENGTH (micrometers)

InfraredVisibleUV

GHGs Concentration Life time GWP Anthropogenic source1750 1998 (Years)

CO2 (ppm) 280 360 120 1 Fossil fuel, respiration, cement production

CH4 (ppb) 700 1745 14.5 23 Fossil fuel, rice paddy, waste dump, live stock

N2O (ppb) 270 314 120 296 Fertilizer, industrial processes, combustion

CCl2F4 (ppt) 40 80 >50000 5,700 Liquid coolants

CCl2F6 (ppt) 0 3 10000 11,900 Liquid coolants

SF6 (ppt) 0 4.2 3200 22,200 Dielectric fluid

TroposphericOzone (ppt)

25 34 0.01-0.05 ----

Overview on greenhouse gases conc., life time, GWP (global warming potential) and anthropogenic source

(IPCC, 2000)

Greenhouse gases absorb infrared radiation and prevent it from escaping to space.

Carbon dioxide, methane, and nitrous oxide are very good at capturing energy at wavelengths that other compounds missed.

Three ways to reduce greenhouse gases

• Emission reduction: switch to better technologies with lower emissions

• Emission substitution: replacing fossil fuels with renewable energy

• Off-setting by sequestration: biotic uptakes from the atmosphere (e.g. tree planting)

Potential Agricultural-Related Impacts from Climate Change

• Droughts and low water-tables leading to water stress• Transport of water to other locations• Warmer temps leading to more pests and diseases• Changing seasons will lead to different crop growth• Soil temperatures will remain warmer

Impacts

Socio-economic impacts:• decline in yields and production;• reduced marginal GDP from agriculture;• fluctuations in world market prices;• changes in geographical distribution of trade regimes;• increased number of people at risk of hunger and

food insecurity;• migration and civil unrest.

Impacts

Biophysical impacts:• physiological effects on crops, pasture, forests and

livestock (quantity, quality);• changes in land, soil and water resources (quantity,

quality);• increased weed and pest challenges;

More impacts• Additional CO2 is expected to improve crop yield and

biomass production.

• Crops that are currently near climate thresholds (e.g., wine grapes) are likely to suffer decreases in yields, quality, or both.

• Climate change is expected to improve growing conditions for some crops that are limited by length of growing season and temperature.

Reasons for Crop Increases• Longer growing season• Warmer spring soil temperatures• Modest or no increase in summer daily maximum temperatures• Increase in nighttime temperatures• More precipitation• More soil moisture• Higher dew-point temperatures reduces moisture stress• Increased carbon uptake by crops• Higher CO2 increases the water-use efficiency of crops

Reasons for Crop Decreases

• More precipitation extremes– More rain events bring heavy rain– More droughts– More floods

• More over-wintering pests• More pathogens due to higher humidity• More vigorous weed growth• More efficient water use => less cooling

Mitigations for agriculture

Mitigations for agriculture

Individual actions

Use mass transit, bike, walk, roller

skate

Tune up your furnace

Unplug appliances or

plug into a power strip and

switch it off

Buy water-saving appliances and

toilets; installing low-flow shower

heads.

Caulk, weather strip, insulate,

and replace old windows, air

condition

Buy products with an Energy

Star label

Climate Change and Vegetables

R. Mavlyanova

Vegetables are the best resource for overcoming micronutrient deficiencies and provide smallholder farmers with much higher income and more jobs per hectare than staple crops.

(AVRDC 2006)

High temperaturesTemperature limits the range and production

of many crops. In the tropics, high temperature conditions are often prevalent during the growing season and, with a changing climate, crops in this area will be subjected to increased temperature stress.

(Bell et al. 2000)

DroughtUnpredictable drought is the single

most important factor affecting world food security and the catalyst of the great famines of the past (CGIAR 2003).

The world’s water supply is fixed, thus increasing population pressure and competition for water resources will make the effect of successive droughts more severe (McWilliam 1986).

SalinityVegetable production is threatened

by increasing soil salinity particularly in irrigated croplands which provide 40% of the world’s food (FAO 2002).

FloodingVegetable production occurs in both

dry and wet seasons in the tropics. However, production is often limited

during the rainy season due to excessive moisture brought about by heavy rain.

Most vegetables are highly sensitive to flooding and genetic variation with respect to this character is limited.

(Drew 1979).

Broccoli

Broccoli can tolerate temperatures of 30-32°C so long as night temperature fall to at least 15°C.

However, yield may be reduced by up to 45% due to problems including: blindness, brown head, bracing in the head, catseye, uneven floret size, uneven cluster development, loose clusters.

Often varieties that will grow in hot weather do not have the best quality.

Low temperatures (4 °C) can cause development of water soaked areas, purple colors in the head and premature yellowing. Yield may be reduced by 25%.

BeetrootBeetroot grows best between 18 – 25°C.

It is susceptible to hot temperatures, with 27°C potentially causing bolting, poor color and root shape.

In particular, high temperatures can cause light and dark rings to form in the root (zoning) which is undesirable for processing.

High soil temperatures also increase problems with “damping off” diseases.

The major issue with low temperatures (5°C or less) is exacerbation of nutrient disorders such as boron deficiency, as well as “hollow heart” caused by calcium and boron deficiency.

Beans

Beans require a fairly narrow temperature range in order to maximize productivity. Yields can be 6t/ha at optimum temperatures of 15-21°C.

Above 28 °C, pollen viability is decreased resulting in flower bud drop and reduced pod formation. Pods are also more likely to be fibrous, lacking good flavor and texture.

Temperatures below 10°C result in poor root system development and reduced photosynthesis, potentially halving total yield.

Sweet corn

Sweet corn grows best between 24 – 30°C. Prolonged temperatures above 32°C can reduce

pollen germination to zero, resulting in failure of kernels to develop on the cob.

A few days at 32°C can reduce yield by 30%. Below 12°C sweet corn seeds can fail to

germinate, emergence is reduced, and phosphorous uptake is limited.

Sweet corn is not usually planted until soil temperatures reach 15°C.

Lettuce

Suitable air temperatures range from 12 – 21°C, with 18 °C the optimum.

The most successful lettuce production occurs during periods when there are at least two months with maximum daytime temperatures of 17 – 28°C and night time temperatures not exceeding 15°C.

Lettuce seed will not normally germinate at over 25°C. This issue can be overcome by using seedlings or priming seed in 1% potassium phosphate or water

Lettuce can tolerate low temperatures, even below zero for short periods. However, low temperatures extend the growing period by up to 150 days and can increase the incidence of anthracnose, russetting and external cracking.

Lettuce

Capsicums

Optimal temperatures for capsicum production are 20-25°C, resulting in yields of around 30t/ha (field production).

At high temperatures (32°C) pollen viability is reduced, resulting in lower fruit set.

High temperatures also increase the risk of sunburn, particularly under extreme conditions.

At the lower threshold for capsicum growth (8-10°C) fruit fail to develop normal size and shape.

Modification of climate for crop production

Light modification• Optimum plant population• Leaf orientation – erect leaf• Double row planting method• Green house culture

– Reduction of light intensity– Photoperiod control

• Improve plant for more day neutral or non photosensitivity

• Companion crop

Temperature modification• Altitude-latitude replacement• Green house culture• Improvement for cold and heat tolerance• Cover soil surface with plant material and other material for temperature reducing

• Irrigation system

Wind modification• Wind break

Moisture and evapotranspirtionmodification

• Irrigation system• Mulching• No-tillage• Drought tolerance plant• Artificial rain or rain enhancement

IPCC Summaries for Policymakers: www.ipcc.ch

UW Climate Impacts Group: www.cses.washington.edu/cig

UW Program on Climate Change: http://www.uwpcc.washington.edu/

Climate Solutions: www.climatesolutions.org and www.realclimate.org

AVRDC (1990) Vegetable Production Training Manual. Asian Vegetable Research and Training Center. Shanhua, Tainan, 447 pp.

Thank you for your attention