The changing climate and biodiversity

Global climate is undeniably getting warmer, but the term “climate change” itself is natural and gradual. We are now in the warming phase of the earth before another ice age hits again.

The average pattern of weather, called climate, usually stays pretty much the same for centuries if it is left to itself. What is unusual about the climate change we are recently experiencing is its cause: past climate changes were natural in origin; while human activities, primarily the burning of fossil fuels and clearing of forests, have magnified the intensity of the natural greenhouse effect causing warmer global temperatures than they have ever been during the past five centuries, probably even for more than a millennium. In short, we are advancing the rate of the warming phase of the earth and we are moving forward to the next ice age.

A comprehensive assessment by the Intergovernmental Panel on Climate Change (IPCC) of the scientific evidence suggests that human activities are contributing to climate change, and that there has been a discernible human influence on global climate.

Cutting of trees and reclamation of wetlands are other human-induced activities that contribute to global warming. Trees and plants take carbon dioxide (CO2) and absorb them for photosynthesis and they are often called carbon sinks. Cutting trees would decrease the amount of carbon being absorbed from the atmosphere. Reclamation of wetlands such as mangroves and rice paddies would release the methane stored in these areas into the atmosphere, increasing their concentration and warming the earth.

Natural factors (greenhouse effect, the orbit of the earth around the sun and the tilt on its axis which cause the change in seasons and the amount of solar radiation into the atmosphere) were the past drivers of past climate change. The amount of natural aerosols in the atmosphere is also important because they absorb and emit heat.

Climate change is actually a natural fluctuation and the increase of CO2 is highly caused by human activities. If we look at the estimated global temperature for the past 425,000 years, there’s quite a bit of fluctuation. There are long periods of time when the average global temperature was as much as 9°C degrees colder than now—these were ice ages, the last one was 12,000 years ago. There were also times when it was warmer than today. On the whole, we are in a relatively warm period—which means there are higher carbon dioxide (CO2) concentration—a record high relative to more than the past half-million years, and has done so at an exceptionally fast rate. For more than 10,000 years prior to the Industrial Revolution, CO2 levels in the atmosphere were essentially constant, which shows that the recent increase is not natural, and that there are no known natural sources of CO2 sufficient to account for the recent increase.

Since the early 1800s, when people began burning large amounts of coal and oil, the amount of carbon dioxide in the earth’s atmosphere has increased by nearly 30 percent, and average global temperature appears to have risen between 1°C and 2°C.

Once greenhouse gases’ concentration is higher in the atmosphere than necessary, the Earth becomes even warmer, causing changes in the amount and pattern of rain and snow, in the length of growing seasons, in the frequency and severity of storms, and the rise in sea level. Farms, forests, plants and animals in the natural environment will all be affected.

From the Ormoc Catastrope to the recurring extreme weather disasters we hear from the current news in areas that never experienced landslides and flash floods, is now wakening up to the fact that the changing climate can kill people and destroy properties and the environment along its path.

Everything on earth is interrelated, and because of extreme weather events, disruption of planting and harvesting seasons, and water scarcity, the current rice varieties and cultivation techniques may be inadequate to supply the population. Outbreaks of malaria, dengue and other water-borne diseases may also increase.

Besides increase in global air and ocean temperatures, melting ice caps, and global sea level rise, one of the worstcase scenarios on the effects of climate change to biodiversity is the extinction of several species. Because of their narrow or specialized environmental requirements polar bears and panda bears may not be able to cope with warming of the global climate. Several species may migrate toward the north and south poles. The increase of temperatures in the equator may force plants, through seed dispersal, and animals to migrate toward the poles because the temperature is much more similar to their previous location. The changes in the climate may also disrupt the timing of reproduction and other processes of plants and animals. The synchronization of plants and their pollinators may be disrupted. Hibernating animals such as frogs and other amphibians may be affected in the disruption of the metabolism and body temperature with the change in temperature and seasons.

In the Philippines, an alliance of environmental non-government organizations, which includes Haribon Foundation, is working together to address the climate change issues at the national, regional and global levels. It was formed during the formation of the UNFCCC in order to represent civil society organizations in the negotiations. They advocate policies in the government and private sectors that address climate change with focus on energy development, marine management and land use concerns.

Unfortunately, we cannot stop climate change, but we can do something about the rate at which it is going. If human activities have caused the changing climate, then we ourselves also can also act to minimize the impacts of our environmentally harmful ways. Haribon advocates the planting back of indigenous trees in our natural forests and denuded lands for they are the natural sequesters of CO2.

For more information or inquiries about Climate Change and Biodiversity, e-mail: communication@haribon.org.ph. –Gregorio dela Rosa Jr., Haribon Foundation