2. What is global warming?
3. Greenhouse effect
4. Evidence of global warming/climate change
c) Rise in sea level.
5. Causes of global warming-emissions
6. Sources of emissions
7. Who is responsible for greenhouse emissions?
8. Possible impacts of global warming:
a) Most affected would be marginalized communities,
b) Coastal areas,
c) Frequent and strong storms and floods,
d) Health problems,
e) Ecosystem destruction,
f) Agricultural loss (Food insecurity).
9. Unpredictable surprises
10. Threshold level
11. Strategies to mitigate global warming:
a) Transforming to renewable sources of energy,
b) Energy conservation and efficiency,
c) Individual efforts.
Global warming is simply defined as an increase in the average global temperatures. Though it is an environmental problem, it has serious implications on global economics, geopolitics, society, humanity, and all living beings. “Global warming is one of the most controversial science issues of the 21st century, challenging the very structure of our global society”, says Mark.
Though there have been controversies between two schools of scientific thought, one calling it is a myth and the other considering it is a reality, there is sufficient evidence to support them later. Anthropogenic activities, causing increased emissions of greenhouse gases, are behind global warming.
Global warming means the earth is becoming warmer gradually. There is an increase in average global temperatures of air and oceans, accompanied by widespread melting of glaciers and rising sea level.
The United Nations Intergovernmental Panel on Climate Change (IPCC) in its ‘Synthesis Report on Climate Change’, states that there is clear evidence for a 0.6 0C rise in global temperatures and a 20cm rise in sea level during the 20th century.
It predicts that “global temperatures could rise by 1.4 to 5.8 0C and sea level could rise by 20 to 88cm by the year 2100.”
The majority of the scientists and research organizations, including IPCC, have reached the consensus that global warming is caused by the massive increase of greenhouse gases such as Carbon dioxide (Co2) in the atmosphere resulting from the burning of fossil fuels and deforestation.
Some atmospheric gases: Carbon dioxide (CO2), Methane (CH4), Nitrous Oxide (N2OX), Chlorofluorocarbons (CFC), and water vapors are important to this temperature balance. They form the greenhouse blanket in the atmosphere.
This blanket absorbs some of the longwave radiation and re-radiate it back to the surface, which causes the atmosphere to warm up to 350C. Without these gases, the earth’s atmospheric temperature would be 15 to 200C. If more such gases are added to the atmosphere, the earth’s temperature would increase accordingly. And these are being added enormously.
This is why global warming is taking place at a greater pace due to the abundant increase in emissions. “The scientist’s community is largely persuaded that not only is earth’s climate warming, but the rate of warming is accelerating due substantially to, human activity,” says Dr. Terrence M. Joyce, Senior Scientist and Director of Ocean & Climate Change Institute.
The main evidence of global warming is three basic indicators- temperature, precipitation, and sea level. Firstly, the temperature of the land surface, ocean waters and free atmosphere has been measured through fixed thermometers, balloons in the air, and satellites. By these sources, scientists have produced a record of the last 130 years, which shows global warming of 0.65(+ – 0.05degree C) over this period. We also know that 2010 was globally the warmest year on record.
Secondly, the recorded data of precipitation also reveals that there is an upward trend in global precipitation. It shows that precipitation has increased over land at high latitudes in the northern hemisphere, especially during cold seasons. As the cyclones, i.e. hurricanes, tornadoes, storms are closely related to the process of precipitation; the world has experienced more frequent and stronger hurricanes and storms during the recent past; Hurricane Katrina in the US in 2005 and 2010 Super Flood in Pakistan.
The magnitude of the impacts warrants seriously looking into the responsible factors for emissions in order to devise effective strategies to cope with this peril. There are many sources/agents which are responsible for emissions of greenhouse gases – resulting mainly from the burning of fossil fuels and deforestation. Industrial processes, power generation, transportation, and domestic consumption of fossil fuels are major sources of anthropogenic emissions. Unfortunately, fossil fuels i.e. oil, coal, natural gas supply 85 percent of the energy supply whereas clean forms of energy i.e. nuclear, biomass and hydrogen only form 15 percent of the energy supply.
On the other hand, cutting of trees for settlements and natural fire incidents like the summer fire in Australia and unusual fire in Russia in 2010, due to high temperatures, are also causing deforestation at a massive level. In this way, the forests, which are a major source of balancing CO2, are also decreasing resulting in an increase in the atmosphere.
Since the emissions are proportional to consumption. North America is a leading emitter followed by Europe and Asia. Together they make 90 percent of the global industrially produced CO2. The developed countries have emitted much more than developing countries. Besides, the developing countries are striving for economic progress, subsequently increasing emissions as economic development is closely associated with energy production.
Now, all the countries, particularly developed countries have to share the responsibility to cut the emissions for the purpose of humanity otherwise we are going to suffer the possible implications.
Global warming is going to divest communities that are already the most marginalized in the world. These are the communities that are least responsible for the industrial and historical emissions that created the problem. However, future climate change will have impacts on all parts of human society, including coastal regions, storms, and floods, health and water resources, agriculture, and biodiversity.
One; the coastline regions are most vulnerable. As the UN’s panel on climate has reported that sea levels could rise by 20-88 cm in the next 100 years. This is a serious problem for coastal areas which will be more prone to storms and floods.
In response, the bigger and developed countries would have to build higher walls on the coasts but still, they will have to lose some agricultural land. However, small island countries like the Maldives face dire situations. The sea rise would flood up the dry land, making these islands inhabitable. Another country, Bangladesh which is a deltaic region would lose a considerable portion of land and its agriculture – a prime source of livelihood there will be destroyed.
Two; storms and floods are major natural hazards. The records show that the temperature regions, particularly in the northern hemisphere, have witnessed more storms over the last 50 years. Two-fifth of the world’s population lives under the monsoon belt. This difference will increase and the monsoons, which are normally life-giving rains, would exacerbate tremendously flooding the regions and destroying agriculture – the major economic activity in the developing countries.
diseases and injury due to extreme events; increased frequency of diarrhea and cardiovascular diseases. By far the most important threat to human health is access to fresh drinking water. Though the runoff is projected to increase by 10 to 40 percent by mid-century at higher latitudes the negative impacts of global warming on the freshwater systems outweigh its benefits.
Currently, approximately 1.7 billion people, a third of the world population, live in countries that are water-stressed. IPCC suggests that with the projected global population increase and the expected climate change, five billion people may experience water stress by 2025.
Fourth; the ecosystem which is an essential component for biodiversity is going to be seriously affected by global warming. The species at maximum threat are The mountain gorilla in Africa, amphibious Bengal tiger, polar bears, penguins, etc. The reason for the threat to these species is that they are unable to migrate in response to climate change due to human activity and urbanization. Another example of an ecosystem under threat is coastal protection. There is evidence that the coral reefs are diminishing due to temperature increase; which will disturb the basic food chain in marine life.
Fifth; the most worrying concern of climate change is the effect it will have on agriculture. The world is already facing a food crisis. According to the UN, more than 800 million go to sleep hungry every night. An increase in temperature would have two effects: first, in higher latitudes. It will increase food production due to moderating temperatures and increased CO2; second. Generally, there will be a drop in food production in both the developed and less developed countries.
The above impacts assume that there is a linear relationship between the increase in temperatures and its implications. However, there is increasing concern among scientists that climate change may occur abruptly and explode surprises for humanity- beyond its control.
A report by the US National Academy of Science (NAS) says, “Available evidence suggests that abrupt climate changes. Are not only possible but likely in the future, potentially with large impacts on ecosystem and societies”.
Moreover, there is a point of no return- “threshold”, after which warming may become unstoppable. The earth’s climate can change abruptly when the responsible factors reach the thresholds. Most scientists think that the point lies not far beyond 20C hotter. It is the point at which anthropogenic warming can trigger a huge release of Carbon dioxide from warming oceans. Or similar releases of both CO2 and CH4 from melting permafrost, or both.
To limit warming to 20C we must stabilize the concentration of greenhouse gases in the atmosphere at a specific ‘stabilization level’.
From the Kyoto Protocol 1997 through Copenhagen, 2009 to Cancun Conference 2010, the world leaders have been unable to agree on substantial cuts in emissions and adequate funding for adoption.
Though there has been some progress in foundation work along with commitments from the world leaders to tackle this danger to planet earth, there is a long way to go for effective action.
The solar energy available is the most abundant form of energy available to humans. Wind energy is another plenty source of energy. The nuclear source is also a non-pollutant source of energy.
We need to understand that we have to switch over to these sources of energy as fossil fuels are bound to be finished by the increasing levels of consumption; so why late, why not now?
Furthermore, the effort at the international level is not the only way to control global warming; all the people can play their individual roles as well. Individuals can help reduce greenhouse emissions in many ways like driving less, sharing a car with a friend or colleague to the office, eating locally.
Improving vehicles’ fuel efficiency, consuming less, using less electricity (and saving money), energy efficiency at work and home, and reducing waste products. These acts would serve the purpose of emission reduction in two ways: One; less- consumption would result in less production and subsequently less burning of fuels. Two; it will generate moral pressure on the industries and governments to realize the dilemma and agree to the emission reduction policy.
Ultimately, a combination of improved energy efficiency and alternative energy resources is the way to mitigate global warming.
Global warming has become the real test of the foundations of our modern society, civilization, and democracy. The solutions are at hand. Therefore, the world leaders have a responsibility to respond to it effectively for the cause of humanity – our future generation. “Climate change, and what we do about it, will define us, our era, and ultimately the global legacy we leave for future generations”, says Ban Ki-Moon.