Climate change and causes of Global Warming

Climate change defined as: “Long term weather patterns and trends becoming different over an extended period of time”

For example if the average temperature in Pakistan  over the 20th century is significantly higher or lower than the average temperature in Pakistan over the 19th century this would be an example of climate change.

Global warming and climate change in reality the two terms means different things have both been used for decades. Climate change again as the name suggest, refers to the changes in global climate which result from increasing average global temperature. For example changes in precipitation patterns, increased prevalence of drought, heat waves and other extreme weather etc. In general there are 10 indicators with the help of which we can detect climate change and global warming. There are 7 indicators that would be expected to increase in a warming world and 3 indicators would be expected to decrease.

Changes in climate can result from both natural events and human activities. Examples for natural events are volcanic eruptions, variation in earth’s orbit around sun and variation in solar output. Examples for human induced causes are industrial pollutant and fossil fuels, warming of average annual temperature due to urbanization and changes in earth’s albedo due to deforestation of tropical rainforest.

Earth temperature depends on the balance between energy entering and leaving the planet’s system. When incoming energy from the sun is absorbed by earth system, Earth warms when energy is reflected back into the space. Earth avoids warming when energy is released back into the space. Earth cools many factors both natural and human can cause changes in earth’s energy balance.

Our lives are connected to the climate. Human societies have adapted to the relatively stable climate we have enjoyed since the last ice age which ended several thousand years ago. A warming climate will bring changes that can affect our water supplies, power and transportation system, natural experiments and even our own health and safety. Carbon dioxide can stay in atmosphere for nearly a century so earth will continue to warm in coming decades. The warmer it gets, the greater the risk for more severe changes to climate and earth’s system. It is difficult to predict the exact impacts of climate change.

Global warming effects on multi sectors of Pakistan

Agriculture and fisheries are highly dependent on specific climate conditions. Increase in temperature and carbon dioxide can be beneficial for some crops in some places but to realize these benefits, nutrient levels, soil moisture, water availability and other conditions must also be met. Changes in the frequency and severity of droughts and floods could pose challenges for farmers and ranchers. Meanwhile warmer water temperatures are likely to cause the habitat ranges of many fish and shellfish species to shift which could disrupt ecosystem. Overall climate change could make it more difficult to grow crops, raise animals and catch fish in the same ways and same places as we have done in the past.

Weather and climate play a significant role in people’s health. Changes in climate affect the average weather conditions that we are accustomed to warmer average temperature will likely lead to hotter days and more frequently and longer heat waves. This could increase the number of heat-related illness and deaths. Changes in temperature, precipitation patterns and extreme events could enhance the spread of some diseases.

Climate is an important environmental influence on ecosystems. It affect ecosystem in variety of ways. Warming could force species to migrate to higher latitudes or higher elevations where temperatures are more conductive to their survival. Similarly as sea level rises, saltwater intrusion into a freshwater system may force some key species to relocate or die.

Climate change directly or indirectly affects the growth and productivity of forest. Directly because, due to change in atmospheric carbon dioxide and climate and indirectly through complex interactions in forest ecosystem.

Energy plays an important role in many aspects of our lives. Our energy production and use is interconnected with many other aspects of modern life such as water consumption, use of goods and services, transportation, economic growth, land use and population growth. Our production and use of energy also contributes to climate change

Water resources are important to both society and ecosystems. We depend on a reliable, clean supply of drinking water to sustain our health. We also need water for agriculture, energy production, navigation, recreation and manufacturing.

Climate change and global warm has a significant effect on raining pattern. Monsoon rains in Pakistan is the major rainfall season in Pakistan which has been adversely effected by the climate change, the monsoon season has not only shifted but the intensity of rainfall and area or region has also changed, last year 1400 died in floods, 13,000,000 people displaced.

Due to climate change and global warming, there is an overall increase in the climate of northern areas of Pakistan; this cause an increase in the rate with which glaciers melt this reduces the Ice Reserves for our home country. In the major cities of Pakistan like Karachi, Islamabad, Rawalpindi, significant increase of temperature and climate can be observed.

One of vary significant effect as observed in Pakistan is the formation of artificial Attabad Lake in Baltistan due to severe land sliding and snow storm. According to IPCC study for countries most at risk from climate related threats. Pakistan rated 7th in flood, 12th in agriculture.

Extreme weather and its effects on climate change

Catchments, rainfall variability and extreme weather events have become two important factors for policymakers. The variability can exist at various time-scales ranging from seasonal, sub-seasonal to long term climate change.

In Pakistan, a large part of the economy and agriculture relies mostly on water resources. Agriculture accounts for one fourth of Pakistan’s GDP and employs not less than 40% of the labor force. The irrigation system of the country depends on the precipitation in the Himalayas and the monsoon rainfall. Extreme weather events show a lot of variability in the region especially during the monsoon season, but limited research has been carried out to better understand these changes.

Floods and other natural disasters may result in loss of infrastructure, energy insecurity, political and economic instability and deterioration of natural ecosystems in the country.

In this situation, sustainable development is the only way forward to face both natural and man-made disasters.

Water scarcity is also becoming a major threat. Due to the changes in climate variability, extreme weather events (flood risk) are more likely to increase. These extreme weather events had devastating impacts on the country’s economy in the past. One example of this is the recent flood in 2010.

The history of floods in the region extends back to the dawn of human civilization, primarily affecting the settlements near the rivers. The occurrence of these events is more frequent in the South-Asian Region, where the most densely populated area has shown more uncertainty in the last few decades. Pakistan suffered major floods in 1950, 1956, 1973, 1976, 1988 and 1992. In each case, a million hectares of agriculture land was inundated and millions of houses were demolished.

Devastating flood events not only destroy the cultural landscape but also break the continuity of sustainable development. This makes vulnerable villages and towns less sustainable due to the loss of economy, infrastructure and livelihood. As a result of flooding, hundreds of thousands of people migrate to neighboring villages and towns, which create an extra burden on public services. There is also evidence from a number of studies that malaria incidence is positively correlated with such extreme rainfall events.