PENGARUH PERUBAHAN IKLIM TERHADAP KUALIT

(1)

PENGARUH PERUBAHAN IKLIM

TERHADAP KUALITAS AIR

Makalah disampaikan pada FGD tentang ADAPTASI DAN MITIGASI PERUBAHAN IKLIM PADA PERAIRAN DARAT Studi Kasus ekosistem Perairan Situ dan Danau,

Bogor, 4 November 2015 Hefni Effendi

Kepala Pusat Penelitian Lingkungan Hidup (PPLH-LPPM), IPB

Ketua Badan Kerjasama Pusat Studi lingkungan Indonesia (BKPSL)

(2)

Presentation Outline

1. Climate Change

2. Climate Change Impact

3. Climate Change Effect on Aquatic Ecosystem

(3)

(4)

Climate Change

•

Climate change is caused by greenhouse gasses

GHGs , hi h e ha e the gree house

properties

of the earth’s at osphere.

•

These gasses allow solar radiation from the sun

to travel through the atmosphere but prevent

the reflected heat from escaping back into

space.

(5)

(6)

(7)

(8)

(9)

(10)

(11)

(12)

(13)

-1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6

1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100

Temperature Change (oC) from 1990

A: Observations, Northern Hemisphere, Proxy data B: Global Instrumental Observations

C: IPCC 2001 Scenario Projections (SRES)

A B C

1.5 – 5.7 oC

(14)

Climate Change



Scientists around the world now agree that

the climatic changes occurring

internationally are the result of human

activity.



Responsibility for the causes of climate

change rests primarily with the developed

and industrialized nations.

(15)

(16)

(17)

Source: California – Department of Water Resources. Climate Change in California Fact Sheet

(18)

Climate Change Impact

Ecosystem



Changing temperatures will cause ecosystems to

shift

–

forests, land types.



Plant species will dieback in some areas as

temperatures rise, but increase in other areas.

(19)

Climate Change Impact

(Anonymous, 2007. Climate change and water resources)

Agriculture



Declining crop yields are likely to leave

hundreds of millions without the ability to

produce or purchase sufficient food

supplies, especially in Africa.



At mid to high latitudes, crop yields may

increase for low levels of change in

(20)

Health



Higher temperatures expand the range of

some dangerous vector-borne diseases, such

as malaria, which already kills one million

people annually, most of whom are children

in the developing world.



Further, heat waves associated with climate

change and increases in water borne

(21)

Coastline

 Melting ice and thermal expansion of oceans are the key factors driving sea level rise.

 In addition to exposing coastlines, where the majority of the human population live, to greater erosion and flooding

pressures.

 Rising sea levels will also lead to salt water contamination of groundwater supplies, threatening the quality and quantity of freshwater access to large percentages of the population.

(22)

Climate Change Impact

Water

 Rising global temperatures will lead to an intensification of the hydrological cycle.

 Resulting in dryer dry seasons and wetter rainy seasons.

 Subsequently heightened risks of more extreme and frequent floods and drought.

 Impacts on the availability of water, as well as the quality and quantity of water that is available and accessible.

 Melting glaciers will increase flood risk during the rainy season, and strongly reduce dry-season water supplies to one-sixth of the

(23)

Climate Change Impact



Latin America:

temperatures are predicted to increase by between 0.2- 2 oC (low estimate) to 2- 6 oC (high estimate) in the next century. El Niño events will increase in frequency and severity during summer months, and some areas will

experience hot and cold waves.



Africa:

greater climate variability, and increasing frequency and intensity of severe weather over the next 50 years. The northern and southern latitudes will become dryer and the tropics will become wetter.

(24)

Effect of climate change on Tropical Asia

(IPCC, 2001)

•

Changes to hydrological regime.

• I reased floodi g, ater loggi g, sali ity aused y

higher runoff in some river basins.

• De reased surfa e ru off i so e asi s due to

increased evaporation.

• Cha ges i fresh ater a aila ility i oastal

regions.

(25)

(26)

(27)

•

Much of the solar energy received by the Earth is used to

drive the hydrological cycle.

•

Higher levels of solar energy trapped in the atmosphere will

lead to an intensification of this cycle, resulting in changes in

precipitation patterns.

•

These changes will result in increased floods and drought

which will have significant impacts on the availability of

freshwater.

•

These impacts on freshwater will be further compounded by

rising sea levels, and melting glaciers.

(28)



Climate change is expected to have far-reaching

consequences for

river regimes

,

flow velocity

,

hydraulic characteristics

,

water levels

, inundation

patterns,

residence times

, changes in wetted areas

and

habitat availability

,

and connectivity across

habitats

.



More intense rainfall and flooding could result in

increased loads of suspended solids, sediment yields,

E. coli

and contaminant metal fluxes associated with

soil erosion and fine sediment transport from the

land (Whitehead

et al

., 2009).

(29)



The most immediate reaction to climate change is

expected to be in river and lake water temperatures.



River water temperatures are in close equilibrium

with air temperature and, as air temperatures rise,

so will river temperatures.



There has already been a 1

–

3°C temperature rise

over the past 100 years in large European rivers such

as the River Rhine and the River Danube (EEA,

2007a).

(30)

Rising water temperatures consequences

during Dry and Wet Season



Decreased dry season flow will give less dilution of

nutrient inputs and higher nutrient concentrations

(Whitehead

et al

., 2009).



Higher intensity and frequency of floods and more

frequent extreme precipitation during wet season

events will give increased surface runoff and erosion,

increasing the nutrient load to the surface water

(Jeppesen

et al

., 2009).



Heavy rainfall may account for a significant proportion of

(31)

(32)

Climate Change Effect on Water Quality

(EEA, 2010)



Physical changes,

such as increased water temperature,

reduced river and lake ice cover, more stable vertical

stratification and less mixing of water of deep-water

lakes, and changes in water discharge, affecting water

level and retention time.



Chemical changes

,

such as increased nutrient

concentrations and water colour, and decreased oxygen

content, etc.

(33)

Rising water temperatures consequences

 Lower levels of dissolved oxygen. As the temperature of the water increases, dissolved oxygen levels decrease.

 Increased water colour due to increased input of humic substances as dissolved organic carbon (DOC) from the catchment.

 Increased mineralization and releases of nitrogen, phosphorus and carbon from soil organic matter and increased run-off and erosion will result in increased nutrient loads. Also release of phosphorus from bottom sediments in stratified lakes is expected to increase, due to declining oxygen concentrations in the bottom waters.

 Ammonia levels would fall due to higher nitrification rates. This gives rise to increased nitrate concentrations as ammonia decays to nitrate.

 Increase in algal blooms.

 Loss of aquatic species whose survival and breeding are temperature dependent.  Increase in pathogenic microbes: Sewage overflows upon heavy rains combined

(34)

 Most chemical reactions and bacteriological processes run faster at higher temperatures.

 Temperature controls the growth rates of phytoplankton, macrophytes and epiphytes, making freshwater ecosystems sensitive to rising temperatures.

 Water temperatures also regulate the behaviour of aquatic organisms, such as fish migration, and the timing of

emergence and abundance of insect populations at different life-cycle stages.

 This has implications in that the restoration and improvement of the ecology of streams could be more difficult under future climate change (Whitehead et al_{., 2009).}

(35)