Global Warming and The Enhanced Greenhouse Gas Effect
Did you know: the World Health Organization blames 150,000 deaths per year on the effects of global warming including extreme weather, drought, heat waves, decreased food production and the increased spread of diseases like malaria.
The Earth’s climate is now clearly out of balance and is warming. Many components of the climate system-including the temperatures of the atmosphere, land and ocean, the extent of sea ice and mountain glaciers, the sea level, the distribution of precipitation, and the length of seasons-are now changing at rates and in patterns that are not natural and are best explained by the increased atmospheric abundances of Greenhouse Gases and Aerosols generated by human activity during the 20th century.
As the twenty-first century begins, several well-established environmental trends are shaping the future of civilization. The problems facing us are significant: population growth, rising temperature, falling water tables, shrinking cropland per person, collapsing fisheries, shrinking forests, and the loss of plant and animal species. All of these factors are the result of increasing greenhouse gases caused by human activity, and they will have an exasperating impact on our social, political, economic and environmental systems.
The Enhanced Greenhouse Effect
What is It?
Scientists refer to what has been happening to the earth’s atmosphere over the past decade as the “Enhanced Greenhouse Effect,” referring to invisible gases trapping the sun’s energy beyond what’s natural. Global average surface temperatures increased on average by about 0.6°C over the period 1956-2006. As of 2006, eleven of the previous twelve years were warmer than any others since 1850.
Greenhouse Gases Caused by Human Activity
With climate change, as with ozone depletion, the human footprint on Earth is apparent: carbon dioxide emissions through fossil fuel; methane and nitric oxide gases as a result of farming, industry, and landfill waste; soil and ocean pollution; and deforestation are all tied to the emission of greenhouse gases and runs through modern society. And with an exploding population the problem will only get worst.
During recent millennia of relatively stable climate, civilization became established and populations have grown rapidly.
Between 1950 and 2000, world population increased from 2.5 billion to 6.1 billion, a gain of 3.6 billion. And even though birth rates have fallen in most of the world, recent projections show that population is projected to grow to 8.9 billion by 2050, a gain of 2.8 billion, with most all this growth coming from developing countries (World Watch Report: Challenges of a New Century p.5).
Consequences of Global Warming
Artic Retreat
“In late summer 2007, reports of ice melting were coming at a frenetic pace. Experts were ’stunned’ when an area of Arctic sea ice almost twice the size of Britain disappeared in a single week.” The observed rapid retreat of Arctic sea ice is expected to continue and lead to the disappearance of summertime ice by the year 2050.
Some scientists believe that global warming may be about to push the Greenland ice sheet over a threshold where the entire ice sheet will melt in less than a few hundred years. If the entire 2.85 million km of ice were to melt, it would lead to a global sea level rise of 7.2 m (23.6 ft). This would inundate most coastal cities in the World and remove several small island countries from the face of Earth.
Recent changes in many physical and biological systems are linked with this regional climate change. Evidence from most oceans and all continents shows warming attributable to human activities.
Rising Temperatures
In the next 50 years, even the lower limit of impending climate change-an additional global mean warming of 1°C above the last decade-is far beyond the range of climate variability experienced during the past thousand years and poses global problems in planning for and adapting to it.
Warming greater than 2°C above 19th century levels is projected to be disruptive, reducing global agricultural productivity, causing widespread loss of biodiversity, and-if sustained over centuries-melting much of the Greenland ice sheet with ensuing rise in sea level of several meters, see IPCC Report AR4 (p. 9).
If this 2°C warming is to be avoided, then our net annual emissions of CO2 must be reduced by more than 50 percent within this century.
Effects on Health
Scientists say that as earth’s thermostat continues to climb, human health problems will only become more frequent. The threats range from emerging tropical diseases to life-threatening temperatures to an increase in allergies and asthma.
Here are some examples of what’s already happening due to global warming:
- In the summer of 2003, an intense heat wave was blamed for an estimated 35,000 deaths across large swaths of Europe. A study says that global warming has doubled the likelihood of heat waves of this magnitude.
- Scientists found in 2008 that poison ivy vines have grown 10 times denser near Savannah, Ga., over the last 20 years. Increased carbon dioxide in the atmosphere causes poison ivy to grow larger and produce stronger irritants.
- Six young men and boys were killed by fatal parasites in 2007 at Lake Havasu, Ariz., after they swam in water infested with a heat-loving amoeba. The Centers for Disease Control and Prevention expect more of these illnesses as global temperatures rise.
- Mosquitoes that carry malaria were found at never-before-seen elevations on Mount Kenya in 2006. As temperatures rise, higher elevations become more hospitable for mosquitoes — and more dangerous for local inhabitants.
Future health problems can also be expected from sea-level rise, increased flooding and stronger storms, among other climate-related threats
A Need To Act Now
Dire Projections
The IPCC AR4 Report lists as either very confident or with a high degree of confidence possible impacts of climate change due to changes in extreme weather and climate events, based on projections to the mid- to late 21st century (see table 2, p.13 for complete listing).
They include: warm spells/heat wave frequency over most land areas; increasing droughts; heavy precipitation events; increased incidence of extreme high sea levels; increases in intense tropical cyclone activity.
These events will take their toll on our way of life, water supply, crop yields, and human mortality rates, especially among the elderly, chronically sick, very young and poor.
With such projections, there are many sources of scientific uncertainty, but none are known that could make the impact of climate change inconsequential. The nation’s ability to prepare for and adapt to new conditions may be exceeded as the rate of climate change increases.
Reducing our vulnerability to these impacts depends not only upon our ability to understand climate science and the implications of climate change, but also upon our ability to integrate and use that knowledge effectively. Changes in our economy and infrastructure as well as individual attitudes, societal values, and government policies will be required to alter the current trajectory of climate’s impact on human lives.
The resolve of individuals, communities, and countries to identify and implement effective management strategies for critical institutional and natural resources will be necessary to ensure the stability of both human and natural systems as temperatures rise.
A Collective Response is Required
Mitigation strategies and adaptation responses will call for collaborations across science, technology, industry, and government, and the actions we can take at home, in our work, or as responsible citizens within a democratic process. For the future of human kind, our children, and their children to come, collectively and as individuals we all share a responsibility to act.