what are the effects of climate change on food production and water resources ? . decline in production . unexpected delay in growth . may cause scarcity in world water reserves . polluted water

What is climate change:
A change of climate that is directly or indirectly related to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability over comparable time periods.

What changes will occur in the temperature:
The most recent scientific assessment by the Intergovernmental Panel on Climate Change (IPCC) estimates that the global averaged surface temperature on Earth will increase by 1 to 3.5°C (about 2 to 6°F) by the year 2100, with an associated rise in sea level of 15 to 95 cm (about 6 to 37 inches).

What are the effects and impacts of climate change:
There is growing global consensus that climate change is humankind’s greatest threat in modern times and is likely to have profound consequences for socio-economic sectors such as health, food production, energy consumption and security and natural resource management.

The harmful impacts of this global warming effect are already manifesting themselves around the world in the form of extreme weather events like storms, tornadoes, floods and droughts, all of which have been mounting in frequency and intensity. As a result, the world today suffers around 400-500 natural disasters on average in a year, up from 125 in the 1980s (Disaster Risk Reduction: Global Review 2007).

According to the Fourth IPCC Assessment Report, the evidence of predicted impacts of climate change is slowly unfolding. Crop yield growth rates are declining in most parts of the world, partially as a consequence of rising temperatures, while increases in prevalence of climate-induced diseases have also been recorded. There is also evidence of accelerating recession of most glaciers on Earth, rainfall variability and changes in marine ecosystems. Another serious threat arising from climate change is to freshwater availability which is projected to decline especially in large river basins and adversely affect more than a billion people by the 2050s

Climate change is also likely to have wide-ranging and mostly adverse impacts on human health. The projected increase in the duration and frequency of heat waves is expected to increase mortality rates as a result of heat stress, especially in areas where people are not equipped to deal with warmer temperatures. To a lesser extent, increases in winter temperatures in high latitudes could lead to decreases in mortality rates. Climate change is also expected to lead to increases in the potential transmission of vector borne diseases, including malaria, dengue, and yellow fever, extending the range of organisms such as insects that carry these diseases into the temperate zone, including parts of the United States, Europe, and Asia.

The observed effects of global warming so far are:

• Increase in the mean global sea level (1-2mm per year over the last century);
• Worldwide retreat of glaciers;
• Decrease in snow cover and thawing of permafrost;
• Shifts of plant and animal ranges;
• Earlier flowering of plants;
• Birds breeding seasons and emergence of insects;
• Increased events of coral bleaching.

Climate change and developing countries:
Developing countries are the least responsible for climate change: The world’s least developed countries contribute only 10 percent of annual global carbon dioxide emissions. However, the geographical location and socio-economic fragility of most of the developing makes them more vulnerable to the environmental, social and economic ramifications of climate change and the lack of resources and capabilities to adapt to the changes will worsen the situation.

Moreover, people who live in poverty around the world will be hardest hit by climate change. This is because the poor are more dependent on natural resources and have less of an ability to adapt to a changing climate.

How is Pakistan affected by climate change:
Pakistan contributes very little to the overall Greenhouse Gas (GHG) emissions, but remains severely impacted by the negative effects of climate change by the following ways:

1. Glacier melt in the Himalayas is projected to increase flooding will affect water resources within the next two to three decades. This will be followed by decreased river flows over time as glaciers recede.
2. Freshwater availability is also projected to decrease which will lead to biodiversity loss and reduce availability of freshwater for the population.
3. Coastal areas bordering the Arabian Sea in the south of Pakistan will be at greatest risk due to increased flooding from the sea and in some cases, the rivers.
4. Being a predominantly agriculture economy, climate change is estimated to decrease crop yields in Pakistan which in turn will affect livelihoods and food production. Combining the decreased yields with the current rapid population growth and urbanization in the country, the risk of hunger and food security will remain high.
5. Endemic morbidity and mortality due to diseases primarily associated with floods and droughts are expected to rise. Increases in coastal water temperatures would exacerbate the abundance of cholera.
6. The impact of climate change will also aggravate the existing social inequalities of resource use and intensify social factors leading to instability, conflicts, displacement of people and changes in migration patterns.

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