The Green House Effect Some gases like CO 2 , Methane, N 2 O, Chlorofluorocarbons (CFCs) etc. naturally exist in the atmosphere, the so called Green House Gases (GHGs) that form a blanket surrounding the earth and keeps the earth warmer. This is called Green House Effect . The Enhanced Green House Effect Human activities (fossil fuel burning, depletion of sinks like forests etc.) has been increasing the concentration of GHGs in the atmosphere and is leading to rise in temperatures . This is called Enhanced Green House Effect. Global Warming/Climate Change The phenomena of a rise in global temperatures of earth and other associated climatic changes as caused by the Enhanced Green House Effect is called “Global Warming” and in broader term “Climate Change”.
Climate Change: Causes and Implications for Pakistan
UNFCCC …..” a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere which is in addition to natural climate variability observed over a comparable period of time”
Increase in Frequency & Intensity of Extreme Weather Events
Uncertainty in Water Availability
Decrease in Crop
Newer perspective for sources of energy
Loss of Biodiversity
Natural Climate Variability Climate Change Natural + Anthropogenic Anthropogenic Influences since the Industrial revolution Spiraling Population High pace of Industrialization Increasing use of Fossil Fuels in Industry & Transport Deforestation for Agriculture and Urbanization
Green House Gases (GHGs) SIX types of greenhouse gases with different Global Warming Potential (GWP). Usually expressed in CO2-equivalent : Carbon dioxide GWP: 1 Hydrofluorocarbons GWP: 11,700 Methane GWP: 21 Sulphur hexafluoride GWP: 23,900 Nitrous oxide GWP: 310 Perfluorocarbons GWP: 9,200
Sector wise Energy Consumption of Pakistan Source: Pakistan Energy Yearbook 2008
Change in CO 2 Emissions in Pakistan (1971-2006)
Glaciers in Pakistan cover 13,680 sq. km which is 13% of mountain regions of the Upper Indus Basin (UIB).
Melt water from these Glaciers contributes more than 60% to the flows from UIB.
International Commission for Snow and Ice (ICSI) “ (1999): Glaciers in Himalayas are receding faster than in any other part of the world and, if the present rate continue, the likelihood of them disappearing by the year 2035 is very high”.
Hewitt (2005): reported widespread evidence of glacier expansion in the late 1990s in the Central Karakoram, in contrast to a worldwide decline of mountain glaciers.
Some Projected Changes in River Flows due to Melting of HKH Glaciers (As reported in recent studies)
World Bank (2006): Western Himalayan glaciers will retreat for the next 50 years causing increase of Indus River flows. Then the glacier reservoirs will be empty, resulting in decrease of flows by up to 30% to 40% over the subsequent fifty years.
IPCC AR4 (2007): Glacier melt in the Himalayas is projected to increase flooding within next two to three decades. This will be followed by decreased river flows as the glaciers recede.
These conflicting findings make the impact of climate change on Karakoram glaciers and Indus River flows very uncertain.
Impact of Climate Change and Glacier retreat on Indus Flows Assumed Climate Change Scenario (CCS): Temp: +3°C, Glacier Area: - 50% Main Results: 1. Annual flows reduced by 15% 2. Intra-Annual flow pattern considerably changed
Some insect pests and diseases proliferate under high rainfall conditions (e.g Bollworm of Cotton, and Wheat Rust and Root Rot diseases), while others thrive under warm moist (e.g thrips) and dry conditions (e.g. locust)
At higher elevations, fisheries are likely to be adversely affected by lower availability of oxygen due to a rise in surface air temperatures.
In the plains, the timing and amount of precipitation could affect the migration of fish species from the river to the floodplains for spawning, dispersal, and growth (FAO, 2003)
Future changes in ocean currents, sea level, sea water temperature, salinity, wind speed and direction, and predator response to climate change have the potential to substantially alter fish breeding habitats and food supply for fish and ultimately the abundance of fish populations in Asian waters
Inundation of coastal areas will pose risk to Mangrove forests, coral reefs breeding ground of fish and infrastructure
Upstream intrusion of saline water in the Indus delta will pose risk to agriculture, fresh drinking water and livelihood of dependant communities, thousands of hectares of fertile soil will become saline
Temperature increases could also adversely affect local flora and fauna of coastal areas, as well as the biological equilibrium of marine life.
Even with drastic reductions in greenhouse gas emissions, sea level will continue to rise for centuries beyond 2100 because of the long response time of the global ocean system.