Climate change dimension

The climate change dimension of the Indicator Framework reflects MRC’s recognition that climate change has great bearing on the long term sustainable development, utilisation, conservation, and management of the Mekong Basin’s water and related resources. Adaptation Capacity across Member Countries is variable with many communities vulnerable to the effects of an increased frequency of extreme events, particularly floods, droughts and storms, as well as sea level rise. In their Nationally Determined Contribution submissions and National Communications to the United Nations Framework Convention on Climate Change, all countries identified adaptation priorities across a range of domains, in particular in areas of disaster preparedness, emergency response, and in agriculture and other natural resource sectors. Three strategic indicators supported by eleven assessment indicators have been selected to monitor key aspects of climate change and the extent to which adaptation measures are in place.

↓ Scroll down to view the three strategic indicators supported by eleven assessment indicators

Note: The selected findings presented here should be interpreted considering the assumptions, methodologies and data sources of the SOBR 2018. For complete assessments, consult the SOBR 2018 report.

Greenhouse gas emissions

Assessment indicators:

  • GHG emissions from LMB water-related sectors
  • Relative contribution to global emissions

Greenhouse gas emissions in the LMB countries currently contribute less than 2% of global emissions. A initial estimate is that for the LMB this is far below 1% compared to total global emissions. However, emission rates are growing faster than the global average due to rapidly developing economies and high rates of population growth. Electricity generation, industry, transportation, and agriculture are the main sectors contributing to GHG emissions.

Greenhouse gas emissions per country since 1990 (Mt CO2)

User guidance: You can interact with the chart by clicking moving the cursor over the lines.

↑ Chart description: GHG emissions are often reported with and without the effects of land use change and forestry (LUCF). For two LMB countries (Thailand, Viet Nam) the difference between including or excluding LUCF is relatively small. For Viet Nam the contribution of LUCF has been always positive in the sense that LUCF were a sink. Till 2001 total CO2e emission for Viet Nam was even negative, so more GHG was captured than emitted. For Cambodia and Lao PDR about 50% of total emission can be attributed to changes in land use change and forestry activities.

Climate change trends and extremes

Assessment indicators:

  • Tropical storm frequency and storm surge risk
  • Changes in temperature
  • Changes in precipitation
  • Extent and severity of flooding
  • Extent and severity of drought

A variety of trends have been examined in order to understand the extent of climate change already occurring within the LMB.

Tropical storms show either an increasing or decreasing trend and are likely to remain constant. However, with rising sea levels the impact of storms might be greater, with a greater extent of damage. Temperature is gradually increasing by about 0.2°C per decade following the global trend. Whilst the number of cold days is expected to decrease, as yet the number of hot days in a year exhibits no clear pattern.

As yet, clear evidence for changes in precipitation patterns have also not been found, which aligns with IPCC projections. However, a small increase in annual precipitation might occur after 2050. The extent and severity of flooding remains a critical component of the LMB and needs to be monitored carefully. However, for the last ten years, no clear trend can be seen in the extent of flooding, possibly as a result of increased regulation. In the future, MRC basin-wide assessments of climate impact on flood behaviour suggests that flooded areas might increase by 2060 for floods of all return intervals by between 4,6% and 27.3%.

In the Mekong Delta, the most important factor related to flooding is expected to be sea level rise. Estimates indicate that approximately 30% of the delta would be inundated with a one metre sea level rise. The recently prepared Mekong Delta Plan of Viet Nam provides a long- term vision and strategy for the development and management of the delta in the face of climate change. The extent and severity of drought show a more favourable trend, suggesting that drought conditions seem to be decreasing slightly, although models predict a potential increase in the future due to rising temperatures and changes in rainfall patterns.

An overall judgement regarding the strategic indicator “climate change trends and extremes” is that climate change is already occurring in the LMB, particularly in terms of rising temperatures and sea levels, and needs to be high on MRC’s agenda.

Changes in flooded areas between 1984 and 2015

↑ Map description: To assess the trend in flooding extent the Water Occurrence Change Intensity product is used. The map shows where surface water occurrence increased, decreased or remained invariant between 1984 and 2015. Both the direction of change (i.e. increase, decrease or no change) and its intensity are observed. The figure shows clearly that for some regions in the LMB flooding has intensified and for other regions it has decreased but the overall trend shows an increase in flood extent.

Adaptation to climate change

Assessment indicators:

  • Institutional response to the effects of climate change
  • Drought Protection
  • Coverage of disaster warning systems
  • Vulnerability to floods and droughts

Adaptation to climate change is defined as the extent to which the basin community is taking action to prepare and live with the effects of climate change. A number of possible actions have been reviewed.

In terms of institutional response to climate change, all Member Countries have developed policies, strategies and/or plans to respond to climate change, and have established both operational and oversight bodies to oversee adaptive actions. Furthermore, all Member Countries have ratified the United Nations Framework Convention on Climate Change (UNFCCC) and have submitted at least two National Communications to the Convention, acknowledging the importance of climate change adaptation and stressing the need for increased research in order to develop and implement effective response measures.

Key national policies, strategies, and institutional arrangements for mainstreaming climate change adaptation

In addition, all four countries have ratified the Kyoto Protocol. At a regional level, in 2018 the MRC released the Mekong Climate Change Adaptation Strategy and Action Plan (MASAP), which provides guidance on climate change mainstreaming and implementation adaptation measures across the LMB.

With regard to physical measures to address climate change, drought protection is provided by irrigation facilities and through storage of water. At present, approximately 36% of land cultivated for rice and maize (the main food grain crops) is provided with irrigation. Water storage in the basin (including in China) is approaching 14% of the mean annual run-off, which is planned to increase to over 20% in the next two decades. Few data are available on the extent of (and investment in) flood protection works, although clearly much work has been done, particularly in the main flood plains.

Disaster management at regional level is provided by MRC through the Regional Flood Management and Mitigation Centre in Phnom Penh. The centre supports Member Countries on disaster management throughout the LMB and provides flood forecasting over an area of approximately 43,000 km2 in Cambodia and Viet Nam, where the basin’s highest population densities can be found.

Studies are ongoing to identify the vulnerability of people as well as infrastructure to floods and droughts and other climate change factors within the LMB. Understanding these relationships is a prerequisite to determining the extent of vulnerability to climate change and what to do about it.

Clearly, each government has shown its commitment to tackling the issue and the next step is to ensure that spatial and development planning in the LMB fully mainstreams climate change concerns in a coordinated and consistent manner.