Earth Temperature and Climate Change

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

These factors have caused Earth’s climate to change many times.

Scientists have pieced together a record of Earth’s climate, dating back hundreds of thousands of years (and, in some cases, millions or hundreds of millions of years), by analyzing a number of indirect measures of climate such as ice cores, tree rings, glacier lengths, pollen remains, and ocean sediments, and by studying changes in Earth’s orbit around the sun.

This record shows that the climate system varies naturally over a wide range of time scales. In general, climate changes prior to the Industrial Revolution in the 1700s can be explained by natural causes, such as changes in solar energy, volcanic eruptions, and natural changes in greenhouse gas (GHG) concentrations.

Recent climate changes, however, cannot be explained by natural causes alone. Research indicates that natural causes do not explain most observed warming, especially warming since the mid-20thcentury. Rather, it is extremely likely that human activities have been the dominant cause of that warming.

Human activities contribute to climate change by causing changes in Earth’s atmosphere in the amounts of greenhouse gasses, aerosols (small particles), and cloudiness. The largest known contribution comes from the burning of fossil fuels, which releases carbon dioxide gas into the atmosphere.

Greenhouse gasses and aerosols affect climate by altering incoming solar radiation and outgoing infrared (thermal) radiation that are part of Earth’s energy balance. Changing the atmospheric abundance or properties of these gasses and particles can lead to a warming or cooling of the climate system.

Since the start of the industrial era (about 1750), the overall effect of human activities on climate has been a warming influence. The human impact on climate during this era greatly exceeds that due to known changes in natural processes, such as solar changes and volcanic we need to have control on our activities to save our future.


Risks Related to Climate Change

The impacts of climate change on forests will vary widely based on the species involved and other factors.  With increasing CO2, forest productivity will likely increase until other impacts of climate change, such as increased risks of drought, forest fire, pests, and invasive species present additional stressors to forests.  As temperatures rise, the distribution and composition of tree species will continue to shift northward.  In practical terms, this translates into a transition from maple and birch as the preferred tree species to oak and hickory by 2100.  Some species, such as red pine, may completely retreat from the Great Lakes region by the end of the century.

Forest management in the region will need to adapt as the potential impacts become clearer.  Planting species that will provide critical habitat for wildlife while remaining resistant to increased risks from pests is one potential option.  In many cases, the facilitation of new species into the region may be more ecologically sound than the preservation of existing traditional species.

As habitat zones shift northward with temperature, many animal species may also need to migrate north as well.  The Great Lakes will be a barrier for migration to many species and will be a critical obstacle for those unable to adapt.  Wildlife that relies on wetlands may be at greatest risk, as increased evaporation rates may reduce total wetland coverage, and further stress those species.

Fish populations throughout the Great Lakes region may become less diverse.  Warmer water temperatures will likely lead to a decline in Coldwater fish populations as warm water fish populations become more abundant.  The overall productivity in lakes and waterways may be reduced by lake stratification and increased a frequency of hypoxic conditions.

As species distributions change, the conservation of wildlife will require similar shifts in protected natural areas, and accommodations in land use and development may be necessary.   As with changing vegetation, the facilitation of new, ecologically beneficial species into the region is an option.

Lower summer water levels are likely to limit groundwater recharge, cause small streams to dry up, and lead to a reduction in wetlands, resulting in poorer water quality and less habitat for wildlife.

More frequent and intense precipitation events due to climate change may amplify existing land use impacts.  Impervious surfaces impair the natural flood-absorbing capacities of wetlands and floodplains, thereby increasing the risk of flooding and erosion.  As severe storms increase in number and strength, watersheds and other ecosystems adjacent to agricultural and urban environments will be particularly vulnerable to damage and contaminated runoff.

Urban environments may need to allocate more “green” space and use more permeable pavement to alleviate increased flooding and erosion risks from more severe precipitation events.  Appropriate land use practices, such as increasing development density and the expansion of protected areas along waterways, will likely be necessary to alleviate increased risks of erosion and preserve increasingly critical wildlife habitat.

Climate change in Pakistan

As we know climate of the globe is changing not due to natural reasons but due to anthropogenic activities as every country is making contribution towards it. because of some activities on large scale emits greenhouse gasses that are becoming a cause of climate change now a day. Pakistan is one of that countries now but contributes towards it on a minor level as 1% contribution of greenhouse gasses is from Pakistan which are produced by fossil fuels burning as well as from vehicular is one of the vulnerable countries for greenhouse gas emissions.

In Pakistan climate is changing causing a lot of impacts threatening flow rate of water that is coming from melting of glaciers. Millions of lives are under threat due to them such as humans as well as biodiversity and vegetation.

Pakistan greenhouse gas emissions are lower as compared to other countries according to international 2008 these emissions were 310 million tons equivalent to CO2 containing 54% CO2, methane 36%, nitrous oxide 9%, carbon mono oxide 0.7% and volatile organic compounds 0.3%. In Pakistan most of emissions are from energy sector up to 50% almost, 39% from agricultural areas,6% from industrial and 5% from commercial areas. Mostly emissions are from energy sector and agricultural areas. different types of technologies needed to be introduced in energy as well as in agricultural sector to reduce these emissions. A specific amount from budget should be fixed for such type of technologies as well as policies are needed which are needed to be implemented and should be followed by not only industries, agricultural related persons but also by as a citizen.

Threats of global warming in Pakistan are increase in extreme weather events retreating of Himalayas and  Hindu Kush causes increase in floods loss of water due to lack of storage places, water stressed in arid and semi-arid areas due to elevated temperature, decrease in forest cover, increase in saline water intrusion in Indus delta affecting agriculture and mangroves including species of birds and other animals, increase in sea level affecting coastal areas , health issues and food security issues are caused by climate change mainly.In Pakistan polar bears population is greatly affected by climate change because lack of food are becoming a cause of their migration.


Climate Change

Climate change is basically changed in weather patterns that are caused by global warming. Global warming is a warming of globe mean warming of our earth.this warming brings drastic changes in our environment. Reasons behind this warming is 1) Anthropogenic activities

2) Natural activities

3) Malinkoite cycle

Most parts of causing global warming are of humans as man-made things of comfort releasing such gasses. These gasses are greenhouse gasses includes methane (CH4),carbon dioxide(CO2),water vapors(H2O),ozone(O3) and nitrous oxides(NOX).most contribution among them is of water vapors. Methane comes from paddy rice fields as well as from dairy and milk production sources while NOX comes from vehicular emission as well as CO2 also come from different sources causing global warming. Sun rays inform different wavelengths including UV, Visible and infrared comes towards the sun rays fall on the earth some of light is absorbed by atmosphere about 30% ,25% is reflected back and 45%is get to the surface of the earth which after heating earth surface re-radiate to the atmosphere where they are captured in CO2 layer causing warming of the natural activities, these involve such as solar radiation as well as the volcanic eruption . Volcanic eruption contributes for the emission of many of  greenhouse gasses.

Positive and negative feedbacks are involved in global warming. Positive feedback is when global warming causes global warming like if more temperature more evaporation will occur causing more global warming as water vapor is a greenhouse gas. But negative feedback is when global warming causes cooling instead of more evaporation more cloud penetration, less penetration of of the example of positive feedback is polar amplification when ice is melted due to high temperature and albedo become less so warming occurs. Due to this whole climate of an overall globe is changed. Weather patterns have changed now. We can observe it now recent year as a temperature is relatively than previous years. Heat wave in Karachi was also observed bringing about drastic changes.

Effects of such weather pattern and climatic variations are shifting of an ecosystem as species adapted to live in less altitude having a normal cold now due to warming are compelled to shift at more latitudes . Species which are unable to survive live in these conditions are becoming extinct such as polar bears and gullies mots.Change in agricultural production also occur as the weather is changed therefore crops will get affected from it.For this, we need to introduce GM crops. Sea level will decrease as ice will get melted due to warming so sea level  will of the biggest examples are of Antarctica which central ice cap is growing as in mid there is more temperature as compared to poles, therefore, more snow falling in the center than poles. Ice cap of the northern hemisphere has also decreased up to 10.7% since the 1970s.Greenland ice sheet has doubled since 1998.human health effects are that they are suffering from cardiac, respiratory as well as death. Not only humans but plants and animals are also suffering from we need to have control on this. This can be done by two ways either we mitigate  by signing international agreements and limit our emissions or learn to live in such it’s our responsibility as a citizen to protect our environment planting more trees reducing emissions of harmful gasses etc.