Climate Change: Its danger for our production and why it escapes our prediction

Prof. Kees Stigter, Agromet Vision[Netherlands, Indonesia, Africa]

FISIP/RCCC (UI) Depok, 21 May 2015

Climate Change:Its danger

for our production and why it escapes

our prediction

1

2

I am making use of experiencecollected together withProf. Yunita T. Winarto,

FISIP, UI, Depok,her students and our groups

of farmers in Indramayu.

From that perspective this is a joint presentation.

I am a visiting professorin the Universitas Indonesia (UI)

Research Team on Response Farming to Climate Change,

Cluster for Environmental Anthropology

Center for Anthropological Studies

FISIP, UI 3

I am also an affiliated professor

at the Agrometeorology Group,Department of Soil, Crop and

Climate Sciences,University of the Free State,Bloemfontein, South Africa.

Under this nominationI give Roving Seminars

in other African countries. 4

For a start

5

Our planet earth has a unique but complicated climate

that presently is changing due to the influence that our (mankind’s)

activities appear to have on the composition of its atmosphere.

It is called anthropogenic (man made) climate change. 6

The world’s agricultural systems face an uphill struggle in feeding a projected

nine to ten billion people by 2050.

Climate change introduces a significant hurdle in this struggle

7

There is general and widely held scientific consensus

that the observed trends in atmospheric & ocean temperature,

sea ice, glaciers as well as climate extremes,

during the last hundred years, cannot be explained solely

by natural climate processes and so reflect human influences. 8

The argument that what we experience could be

natural climate changecan also be refuted by the fact

that present understanding of cyclic climatology of the past

points to a cooling planet

without the presence of mankind. 9

On the simplest level, the weather is

what is happening in the atmosphere at any given time.

The climate, in a narrow sense, can be considered

as the “average weather”. 10

In a more scientifically accurate way, it can be defined as:

“the statistical description

in terms of the mean and variability

of relevant quantities over a period of time”.

11

One may argue that “global warming” is like “ageing”:

You can reduce the consequences but it will continue to happen.

Stopping it is impossible,so adaptation is necessary.

12

The issues are:

(i) global warming,

(ii) increasing climate variability,

(iii) more (and possibly more severe)

meteorological and climatological extreme events. 13

FACTS

14

Is global warming real?

From worldwide observationsWMO (Geneva) concluded

a long time ago that our planet is warming up.

This has to be considered a fact. 15

The warming up is not the same everywhere because

(i) incoming solar radiation is highest in the tropics

(ii) oceans (and to some extent other large water bodies)

do influence what happens in the lower atmosphere 16

Warming means that the atmosphere

is gaining energy in the form of heat.

From where?

The main source of energy is the solar radiation.

17

IPCC (the Intergovernmental Panel on Climate Change)

has been stressing,with increasing confidence

over the years, that the cause of this heat gain

is an increase of greenhouse gases

in our atmosphere. 18

Processes

19

Our atmosphere gets its energy from two sources:

(i) It is warmed from below by solar energy absorbed

by the earth surface during the day.

This heat gets distributed throughout

the boundary layer.

20

We should here already indicate the difference between

land and water surfaces.

On land, in daytime, a tiny surface layer becomes much warmer,

with the very surface becoming hottest, depending mainly

on water content. 21

In water the absorption is over a certain depth, decreasing with depth.

The water surface therefore does not become very warm from

direct absorption, ocean currents play

a more important role here.

22

We were talking of how the atmosphere gains heat.

(ii) Its gases absorbthe longwave radiation

sent from the earth surface throughout day and night.

This prevents the land surface from overheating. 23

But indeed most additional heat created is

absorbed by the oceans.

The large heat capacity of water

prevents the oceans from overheating.

24

We know this radiation lossfrom a cooling surface

(and the cooling air due to this)in nights without a cloud cover.

When there are clouds, they send roughly as much longwave radiation

back to the earth surface as they receive from that surface, and no or appreciably

less cooling occurs. 25

So we must conclude that our planet is actually

heating up mainlybecause of this absorption

of radiative heatby the greenhouse gases

in the atmosphere.

Increasing greenhouse gases mean additional heating. 26

INTERLUDE

ON SOME DATA

AND WHAT INFLUENCES THEM.

27

Somewhere near 1800 the carbon dioxide

concentration was something as 280 ppm,

while we have recently reached 400 ppm.

It is presently increasing exponentially.

28

From 1960 till 2010 the temperature increase

is estimated to have been less than a degree Celsius

(0.7 ºC, 0.85 ºC since 1880).

29

But the projection for the next 50 years is in the order of one degree

Celsius, with the emissions and

atmospheric contents kept within the range of the IPCC scenarios.30

Even if the concentrations of all greenhouse gases

and aerosols were kept constant

at year 2000 levels, a further warming of about 0.1°C per

decade [so 0.5º C in fifty years]

would be expected.

31

It is generally accepted that,

if for this century the temperature increase

can be limited to 2 ºC,the damages will remain much more limited than when the scenarios give

a 4 ºC increase.32

End of the interlude

33

What do such figures mean in practice today?

Here is an example of Arabica coffee grown on the slopes

of the Kilimanjaro, Tanzania.

Coffee is the world's most valuable tropical export crop. 34

Recent studies predict severe climate change impacts on Coffea arabica (C. arabica)

production.

However, quantitative production figures are necessary

to provide coffee stakeholders and policy makers

with evidence to justify immediate action. 35

Using data from the northern Tanzanian highlands,

it was demonstrated that increasing night time (Tmin) temperature was

the most significant climatic variable responsible for diminishing

C. arabica yields between 1961-2012.

36

The minimum temperature rose in that half century

by between 1 and 1.5 °C.The projection for the next 35 years

for that region is 1.5 °C.

With the minimum temperature at 14 °C,

the yields were about 500 kg beans per hectare. 37

A non-linear (sigmoid) model constructed from data

from local areas with different minimum temperatures

gave the following results:

38

With the night minimum rising to 15 °C, the yields would become

about 450 kg ha-1.

With a night minimum temperature at 16°C this decreases

to about 300 kgha-1.39

While for 17°C this becomes about 100 kgha-1.

This means a prediction of average coffee production

diminishing to 145 kgha-1 by 2060 in those areas of Tanzania.

. 40

In the case of Arabica coffee, a solution could be

to go to higher, still colder grounds,

although this disrupts living conditions

and biodiversity patterns.

41

The same has been observedwith apples in India.

The classical varieties must go higher up,

while new more heat tolerant varieties are sought

to replace themat the lower heights.

42

But if we think about the lowland tropics,

there is no way out apart from crop diversification

and also here finding more heat tolerant varieties.

But that is a lot more difficult.

The following data show how bad the situation is. 43

Rice

Data obtained from a CGIAR umbrella study, the same as used for maize below.

44

Temperatures beyond critical thresholds not only reduce

the growth duration of the rice crop,

they also increase spikelet sterility, reduce grain-filling duration,

and enhance respiratory losses, resulting in lower yield

and lower-quality rice grain. 45

Rice is relatively more tolerant to high temperatures

during the vegetative phase,

but highly susceptible during the reproductive phase,

particularly at the flowering stage.

46

Unlike other abiotic stresses, heat stresses occurring

either during the day or the night

have differential impacts on rice growth and production.

47

High night-time temperatures have been shown to have

a greater negative effect on rice yields,

with a 1 °C increase above critical temperature (>24 °C)

leading to 10% reduction in both grain yield and biomass.

48

High day-time temperatures in some tropical and subtropical

rice growing regions are already close to the optimum levels.

An increase in intensity and frequency of heat waves coinciding

with sensitive reproductive stages can result in serious damage

to rice production. 49

Here is one more example

Maize

The results are from something as 20.000 trials at 123 stations all over

the worldof CIMMYT (Columbia).

50

§ Increased temperature significantly effects

maize yield (P < 0.01).

§ Possible gains in yield with warming

at relatively cool sites.51

§ Significant yield losses at sites where temperatures commonly

exceed 30°C(corresponding to areas

where the growing season average temperatures are >23°C or

average maximum temperatures are >28°C).

52

§ Daytime warming is more harmful to yield than night-time warming.

§ Drought increases yield susceptibility to warming

even at cooler sites.

53

§ Under ‘optimal’ conditions yield losses occur over ca. 65% of the harvested area of maize.

§ Under ‘drought stress’ yield losses occur at all sites,

with a 1°C warming resulting in at least a 20% loss of yield

over more than 75% of the harvested area. 54

The climate predictions discussed are long term ones,

of which knowing the trends is an important issue for

adaptation to the consequences of climate change,

food policies, crop planning, variety breeding and screening,

as well as farming system adaptations and modifications. .55

This knowledge is of course also important for extension policies and all other planning related to agriculture that has to be made

to face climate change.

For farmers these are important issues that can be discussed at “Science Field Shops” for

their long term decision making. 56

For forestry, the climate change-induced

modifications of frequency and intensity of forest wildfires,

of outbreaks of insects and pathogens, and of extreme events

such as high winds and dry spells, may be more important than the

direct impact of higher temperaturesand elevated CO2. 57

Global warming is likely to encourage northern expansion

of southern insects, while longer growing seasons

are likely to allow more insect generations in a given season.

Forests that are moisture stressed are often more susceptible to attacks by insects.58

Of equal importance are the considerations of taking away or adding “trees outside forests”.

Integrating all existing and new landscape ecosystems into a complex climate adaptation-oriented resilience approach appears highly promising,

but also extremely demanding. 59

The ocean affects the rate of climate change and is in turn

affected by it as well.

Global warming could alter inputs of salt water, fresh water, oxygen,

nutrients and pollutants with potentially large consequences for marine ecosystems and species.

60

Changes in currents would also influence

the recruitment of organisms in coastal waters

and offshore waters.

61

It has for example been reported that most of the decline

in the world’s marine fishery landings in 1998 could be attributed to changes

in the Southeast Pacific, which was severely affected

by El Niño.62

What we further need to know

63

The main source of this increase

of carbon dioxide, methane and nitrous oxide

appears to beour activities on this planet:e.g. electricity generation

from coal, cement production and driving cars are presently

the main culprits.64

As to carbon dioxide, measurements show that it has increased

from the start of the industrial revolution,

but that changes in land use have also played an important role by large scale cutting of

vegetation, including trees. 65

This is also why Indonesia has become a large

contributor, by felling trees (sinks of carbon dioxide)

in large scale (mostly illegal) logging,

often planting palm oil trees instead, with appreciably less

carbon dioxide absorption per hectare.

66

It is interesting to note that since the very end of the previous century,

the rate of global warming has reduced

by at least half till something as one third

of the rate in the last 50 years

of that previous century.

67

This has been baptized“the hiatus”, a lack of

continuity in the up going trend of global temperature.

So climate change rates reduce.

Is this going to change our thinking?

68

Our lack of knowledge and understanding is best illustrated with the

discussion on this present global warming “hiatus”.

69

Some deny its very existence

but accurate world wide measurements and

comparisons show that this “hiatus”,

is there, since the late 90s.

70

There have already been four quantitative(!) reasonings of

full fledged explanations:

(i) more volcanic particles in the atmosphere;

(ii) extremely strong large scale western winds

in the Pacific;

71

(iii) much warmer water being transported to deeper

layers of the ocean;

(iv) indeed being in a down going phase of the Pacific Decadal Oscillation and/or

another of such oscillations as surface induced atmospheric

variations/imbalances. 72

It is likely that any of these four explanations

may actually be involved,if not more processes.

But we have no clueabout the ratios of their

contributions.73

It is presently most likely that the cause of this hiatus is indeed

more warmer water going to deeper layers, resulting in a (temporarily?) relatively cooler

ocean surface.

This also shows how important oceanic surface temperatures

are for determination of our climate.

74

Here we also have one of the weakest rings in the chain of

climate predictions.

We know so much less about how the sea surface

temperatures are determined by currents and deep waves than we understand on the

atmospheric resultants.75

Indeed, we have for decades sent radiosondes with balloons

into the atmosphere, but only very recently have buoys

been placed in the Pacific Ocean, particularly in those parts used for climate prediction purposes.

76

But if we look at the predictions of the 2014/2015 weak El-Niño (I will explain),

it appears that the atmosphere sometimes does

not want to behave the way we know it.

That makes the little that is predictable suddenly

also unpredictable.77

Old players enter the scene

78

The El-Niño is a disturbance of “normal” climatological

conditions for many thousands of years.

It has nothing to do (or had nothing to do) with climate change.

79

Now scientists have learned that certain Sea Surface Temperature (SST)

distributions in the Pacific Ocean correspond with El-Niño phenomena,

which gives higher SSTs in these areas.

But El-Niño (meaning the “Christmas child”) was known to the fishermen of Peru for the cold water upwelling

occurring before their cost and giving above normal catches of fish

around Christmas in some years.80

So it are unpredictable ocean currents and deep waves,

that are not understood in sufficient detail, that create the

surface signals for El-Niño’s to occur.

They are very important in short term climate predictions

(one to three months).81

The combined forces of ENSO and global warming are likely to have dramatic,

and currently largely unforeseen,

effects on agricultural production

and food security. 82

Agricultural production in for example quite some

Sub-Saharan countries is strongly influenced by

the annual cycle of precipitation and year-to-year variations

in that annual cycle caused by the

El Niño-Southern Oscillation (ENSO) dynamics.

83

The ENSO actually can swing beyond the “normal” state to

a state opposite that of El Niño, with the trade winds amplified

and the eastern Pacific colder than normal.

84

This phenomenon is often referred to as La Niña.

In a La Niña year, or when a La Niña period occurs,

many Asian regions, such as Indonesia,

that are inclined toward drought during an El Niño,

are instead prone to more rain. 85

Both El Niños and La Niñas vary in intensity from weak to strong. The intervals at which El Niños return are not exactly regular,

but have historically varied from two to seven/eight years.

Now, an El Niño can subside

into a “normal” pattern. 86

At other times it gives way to a La Niña.

In many ways, the ENSO cold phase

is simply the opposite of the warm phase,

but without any symmetryin durations or

severity/impacts. 87

This often holds true also

for the climate impacts of the two.

El Niño, or warm phase, tends to bring drought to countries like Indonesia and Australia, at the west end of the Pacific.

88

The latter influences in Africa

are so called tele-connections,meaning that we don’t know

how or why!

89

But the strong influence of La Niña

at the west end of the Pacific, with abundant rainfall and frequent floods,

among others in Indonesia, does not have its parallel

in West Africa.

90

Now, it appears that the frequency of these phenomena, and how they follow each other, has changed in recent times!

However, we are not able to simulate these actual changes with the models that summarize

our understanding, which at this moment

is still very insufficient. 91

As a consequence of the above,simple growing season

rainfall scenarios are very difficult

to derive from existing raw or simplified (outlook fora!)

climate predictions.

92

93

Vulnerable communities, across the world,

are already feeling the effects of a changing climate.

These communities are urgently in need of assistance

aimed at building resilience to their new situations.

94

They are also in need of undertaking climate change

adaptation efforts as a matter of survival and

in order to maintain livelihoods.

In short: they are in need of what we want to call an urgent

“agrarian/rural response to climate change”.

One of the major problems in guiding rural change,

in a rural response to climate change,

is the low formal level of education that

most farmers have and for which governments

have done very little to upgrade it. 95

But we need improved climate literacy

among farmers and a better trained extension

that can guide farmers in further rainfall monitoring

and rainfall interpretation.

96

But we also need further agro-ecosystem

observations, that, with the rainfall distribution,

seasonal scenarios and results from on-farm experiments

explain yields and yield differences.

97

Since 2010, local farmers in Indramayu, West Java, Indonesia,

were stimulated to measure rainfall in their own plots, on a daily routine basis,

using homemade cylindrical rain gauges,

following routines that were proposed earlier.

98

This has never been a goal in itself.

It should now serve other purposes

in a rural response to climate change.

99

Climate change makes it even more necessary to do

such measurements properly and with high spatial measuring densities.

Doing this with an organized group of well instructed farmers in a region

as part of an extension approach, has the advantages that:

100

• each participating farmer can create a record over the years

in a “climate logbook”;

101

• derivatives as monthly, seasonal and annual totals,

maxima and minima, can be easily obtained, graphically compared

and understood as consequences of climate realities.

102

• higher than usual measurement densities can be obtained;

and

measurements can be compared and discussed in (preferably)

monthly meetings;103

• measurements can be part of a larger extension routine in which other data

are collected as well;

and 

measurements can serve as an input to understanding yield differences

between areas, farmers, seasons and years;

104

• measurements can form a basis for attempts of adaptation to climate change,

particularly in relation to increasing climate (including rainfall) variability

and the occurrence of more (and sometimes more severe)

meteorological and climatological extreme events

(including droughts, heavy rains and floods).

105

This is the way a group of farmers, organized in the

Indramayu Rainfall Observers Club (IROC),

developed a new attitude towards climate realities

in Indramayu region, for the past five years.

106

This was already preceded by more than two years

of comparable trials in Gunung Kidul, Yogyakarta,

by a team of Prof. Yunita, myself and groups of her students,

on which we published a book in 2011.

107

This is all part of a new extension approach

made necessary because the Indonesian extension systems

have not or inadequately been prepared

for the consequences of a changing climate.

108

For the same reasons we are now

extending this to the island of Lombok,

West Nusa Tenggara.

109

In addition to their daily rainfall measurements, these rice farmers

do make and write down agro-ecosystem observations regarding sowing methods,

sowing/planting dates, crop varieties, crop stages and development,

soil properties and soil moisture, including irrigation situations

where applicable. 110

They also include pests and diseases and their developments

(including measures they can take in initial stages),

the results of fertilizer use and pesticide use.

The observations made are noted down on fact sheets that,

with the “climate logbook”, form the historical farm plot records.111

After some time we started to use these observations to predict yields

and after harvesting we discussed whether yield and yield differences

could be understoodfrom these observations and the

monthly seasonal rainfall scenarios that I deliver, as local climate

predictions, from raw NOAA and IRA global/regional ENSO ones. 112

Such “scenarios” have this way been made

part of climate change adaptation attempts

on the islands of Java and Lombok.

113

Two problems haunt seasonal rainfall scenarios for

farmers to increase their resilience:

(i) skill of predictions and

(ii) terminology chosen

for these monthly updated seasonal rainfall predictions. 114

In February 2015, a questionnaire was used to interview 42 farmers that

received the monthly seasonal scenario regularly for six months or more,

and 42 farmers in the same villages that did not receive these scenarios

as a control group. Of those receiving these scenarios,

more than half received them for more than two years and 85%

for more than a year. 115

Of the target group of farmers, more than 93% received

the seasonal scenarios via SMS on their mobile telephone,

while for more than 81% this was the only way they received that information. Of the number of farmers receiving

the seasonal scenarios, 55% understood them regularly or better

but 42% understood them only sometimes. 116

This points to the necessity to improve the scenario messages as to the understanding required.

It could be observed that those receiving the scenarios

for at least two years had a much higher regular or better

understanding than the others. 117

Difficulties were mainly of two kinds:

(i) scientific terminology and (ii) the use of “below normal, normal and above normal” qualifications.

Our farmer facilitators had the role of continuing to explain this, but that has apparently been

insufficiently successful. 118

Of those farmers receiving the scenarios, 55% used them regularly or better but 45% only sometimes or never

in their decision making. The main reasons for not using

the scenarios are that others make the farming decisions

(40% of those providing a reason) or that rain is not their main

source of water (26% of those providing a reason). 119

For only 6% the scenarios were not useful when followed.

Of those that used the scenarios, 84% was satisfied: regularly (16%),

often (28%) or always (41%). Only 16% was satisfied only sometimes.

Of the many positive reasons given for this satisfaction,

69% mentioned the high accuracy of the scenarios and the positive role they plaid in improving farmers’ anticipation.120

It appeared thatfrom the control group

not receiving our scenarios, as well as from the main target group,

only less than 10% used (also) other scenarios,

such as from MoA and BMKG,in their decision making.

121

The above stories revealhow we have started

to assist Indonesian farmers to initiate a rural response

to recognized climate change.

Scaling this up into an as wide as possible “farmer carried movement”

is the next stage we should aim at. 122

The role of the government through proper in-service refreshing of extension and/or farmer trainers,

we have dealt with since 2008 in Roving Seminars at UGM & UI.

However, Indonesian Government Departments/Institutes,

Farmers and Scientists live in different worlds of their own.123