By Henrylito D. Tacio
Is it global warming or climate change?
“Climate change is a better choice than the term global warming because it avoids the misleading implications: that all parts of the world are warming uniformly and that the only dangerous outcome of growing greenhouse gas emissions is higher temperatures,” explains Dr. Rosa T. Perez during the Climate Change Media Workshop held at Davao City recently.
Dr. Rosa is a research fellow of the Manila Observatory. She was one of the scientists who contributed to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), a United Nations body which became a co-recipient of the 2007 Nobel Peace Prize.
“Warming is only the tipping point for a cascade of changes in the earth’s ecosystems,” she continues her explanation. “In addition, climate change better conveys the coexistence of human-made effects with natural climate variability, a more accurate, ‘state-of-the-science’ portrayal of the causes for the phenomenon.”
It was Dr. James E. Hansen of the US National Aeronautics and Space Administration who first raised the problem of climate change. In 1988, he told an American Senate hearing that the greenhouse effect “is changing our climate now.”
The greenhouse effect is a natural warming process. According to Dr. Perez, carbon dioxide and certain other gases are always present in the atmosphere. These gases create a warming effect that has some similarity to the warming inside a greenhouse, hence the name “greenhouse effect.”
Here’s what happens: “Visible sunlight passes through the atmosphere without being absorbed; some are back-scattered. Some of the sunlight striking the earth is absorbed and converted to heat, which warms the surface. The surface emits heat to the atmosphere, where some of it is absorbed by greenhouse gases and re-emitted toward the surface. Some of the heat is not trapped by greenhouse gases and escapes into space.”
Dr. Perez says that human activities that emit additional greenhouse gases to the atmosphere increase the amount of heat that gets absorbed before escaping to space, thus enhancing the greenhouse effect and amplifying the warming of the earth.
“Although the Earth’s climate has changed many times throughout its history, the rapid warming seen today cannot be explained by natural processes alone,” points out Dr. Perez, who has a PhD in Meteorology from the University of the Philippines.
“Climate change is very simple,” noted Dr. Robert Watson, IPCC Chairman. “We are increasing emissions of greenhouse gases and thus their concentrations in the atmosphere are going up. As these concentrations increase, the temperature of the earth rises.”
Examples of greenhouse gases are: water vapor, carbon dioxide, methane, and nitrous oxide. There are also those man-made gases generated during industrial processes like sulfur hexaflouride, hydrofluorocarbons, and perfluorocarbons.
“Our lifestyle has led to the accumulation of greenhouse gases in the atmosphere,” notes the fact sheet circulated during the workshop. “These gases trap heat from the sun, making the earth warmer. Manifestations of a warmer world include rising mean temperatures, sea level rise and increase in the frequency and intensity of extreme weather events like droughts and greater rainfall.”
“Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems,” contends the new IPCC report.
Dr. Perez says that the current carbon dioxide released into the atmosphere is about 40% more than pre-industrial levels. “We are emitting a lot of carbon dioxide faster than the Earth can absorb any excess,” she deplores.
As of 2013, Earth was 0.85°C warmer than temperatures before the Industrial Revolution, the time scientists agree humans started generating large amounts of carbon emissions. The new IPCC report cautions that without changes in greenhouse gas emissions, “climate change risks are likely to be high or very high by the end of the 21st century.”
Some members of the IPCC have come up with a list of consequences of climate change to “make it understandable and to illustrate the issues that have the greatest potential to cause real harm,” the report’s chief author, Chris Field of the Carnegie Institution of Science in California, told the Associated Press.
A boiled-down version of what the scientists say the warmed-up future holds for Earth if climate change continues:
1. Coastal flooding will kill people and cause destruction.
2. Some people will go hungry because of warming, drought and severe downpours.
3. Big cites will be damaged by inland flooding.
4. Water shortages will make the poor even poorer in rural areas.
5. Crazy weather, like storms, can make life miserable, damaging some of the things we take for granted, like electricity, running water and emergency services.
6. Some fish and other marine animals could be in trouble, which will probably hurt fishing communities.
7. Some land animals won’t do much better and that’s not good for people who depend on them.
8. Heat waves, especially in cities, will kill the elderly and very young.
According to the fact sheet, which is published by the Climate Change Commission (which was created under Republic Act 9729), there are two main approaches to address climate change: adaptation and mitigation.
On adaptation, the fact sheet explains: “In human systems, the process of adjustment to actual or expected climate and its effects, in order to moderate harm or exploit beneficial opportunities. In natural systems, the process of adjustment to actual climate and its effects; human intervention may facilitate adjustment to expected climate.”
On mitigation, the fact sheet gives this explanation: “Technological change and change in activities that reduce resource inputs and emissions per unit of output and implementing policies to reduce greenhouse gas emissions and enhance sinks.”
“Climate is changing and will continue to do so,” reminds Dr. Perez. “Currently, the impacts on many sectors are still unclear, but may become more pronounced as warming continues. So, we need to focus on understanding, adaptation, and preparation. We, Filipinos, should reduce their greenhouse gas emissions, but for the right reasons.”
0 Comments
Oldest