International Budget Partnership; viii) FAO Aquastat
2. Key environmental problems and their causes
Cambodia faces a multitude of environmental challenges. Among the most serious are the
combined effects of climate change and construction of large dams on the Mekong and its
tributaries, which will alter the flow regimes of the river and make them more unpredictable.
This will have serious impacts on agriculture and fisheries, the two cornerstones of
Cambodia’s food security and livelihood opportunities.
Other key environmental problems include deforestation, loss of biodiversity and ecosystems,
land degradation, natural hazards and disasters, such as floods and droughts, and water
pollution The degradation of forests and biodiversity is in general due to four key drivers
which are common to the entire Greater Mekong Subregion, namely,6
1. Population growth and increasing population density, along with worsening income
inequality;
2. Unsustainable levels of resource use, increasingly driven by the demands of export-led
growth rather than subsistence use;
3. Unplanned and frequently unsustainable forms of infrastructure development
4. Government policies, along with lack of integrated planning, poor governance, corruption
and wildlife crime on a massive scale.
This negatively affects communities and ecosystems resilience to crises, climate change and
disasters.
6 Adapted from WWF 2013
3
Climate change: Present situation and trends and projected impacts
Cambodia experiences a tropical monsoon climate. The mean annual temperature has
increased by 0.8°C since 1960, a rate of around 0.18°C per decade. The rate of increase is
most rapid in the drier seasons and the frequency of hot days and hot nights has increased
significantly since 1960 in almost every season. Projections of mean annual rainfall from
different models are broadly consistent in indicating increases in rainfall for Cambodia. This
increase is mainly due to the projected increases in wet season rainfalls. Cambodia’s coastline
may be vulnerable to sea‐level rise. Sea‐level in this region is projected by climate models to
rise by 0.18 to 0.56 m in the 2090s, relative to 1980‐1999 sea level:7
The expected impacts of climate change will not be completely novel, rather it is likely that
they will compound and multiply current problems and stresses on communities and
ecosystems. Sea-level rise will worsen the salinization of surface and groundwater resources
that is already identified as a problem in all of Cambodia's coastal provinces and one effect of
climate change will be to augment this existing problem. In addition to salinization, sea-level
rise is expected to increase coastal erosion and may lead to the inundation of economically
important coastal infrastructure as well as increase flooding from storms and storm surges.
It is unclear exactly what effect climate change will have on floods and droughts, due in large
part to uncertainty over changes to the monsoon regime.8
It is clear however that the
hydrological regime upon which inland fisheries depend will change, in particular in the case
of the Mekong, which receives much of its flow from glacier melt from the Himalayan and
Tibetan mountain ranges which will become increasingly less reliable. This may make the
annual flooding of the Mekong River and Tonle Sap Lake less predictable, and at present it is
the unpredictability of floods and droughts that causes the greatest problems, rather than the
severity of the events themselves. This condition is also made worse by dam construction on
the upper Mekong (i.e. in the Yunnan province of China) and should the countries in the
lower basin fulfill their plans for further water infrastructure construction on the mainstream
the situation for Cambodia, being a downstream country, would face huge difficulties in
predicting water regimes in the face of climate change and human interference with the river’s
ecosystem.
Climate change impacts on livelihoods
The changes to the length of seasons, combined with the delayed onset of the wet season after
a longer dry season, will affect traditional cropping practices meaning that huge undertakings
for changing farming methods must be budgeted planned for and implemented.
Increased incidence of livestock disease is also predicted, largely associated with lack of
water and grazing land and the long distance to water sources for livestock. Because larger
livestock are an important investment and means of savings for farmers, these kinds of
impacts can have serious consequences and push people into debt and reduce their financial
safety nets, which exposes them to an inability to access cash when faced with other crises.
Impact on rice yield is predicted to be significant9
, yields will decrease under both high and
low emission scenarios, not least because of increased incidence of pests and disease.
Cambodian capture fisheries are especially vulnerable to the changes in temperature and
hydrological flows that are associated with climate change. Such changes could have
significant impacts on migration, breeding and spawning patterns while also adding pressure
to critical fisheries habitats. In addition, the future of the fisheries sector is also uncertain due