The Philippine Climate Change Commission’s National Framework Strategy on Climate Change (NFSCC) 2010-2022 refers to climate change as a change in climate that can be identified by the changes in the mean and/or variability of its properties and that persists for an extended period typically decades or longer, whether due to natural variability or as a result of human activity.
Global warming is one of the major evidences of climate change that result to increase in sea levels, increase in temperature and acidity of oceans, melting of ice caps, higher incidence of hurricanes, droughts typhoons and forest fires, and spread of climate-related diseases.
Besides natural cycles and events, the effect of greenhouse gases (GHGs) emitted by humans is blamed for the drastic changes in climatic conditions worldwide. The main sources of GHGs due to human activity are:
- burning of fossil fuels and deforestation leading to higher carbon dioxide (CO2) concentrations in the air. Land use change (mainly deforestation in the tropics) account for up to one third of total anthropogenic CO2 emissions.
- livestock enteric fermentation and manure management, paddy rice farming, land use and wetland changes, pipeline losses, and covered vented landfill emissions leading to higher methane atmospheric concentrations. Many of the newer style fully vented septic systems that enhance and target the fermentation process also are sources of atmospheric methane.
- use of chlorofluorocarbons (CFCs) in refrigeration systems, and use of CFCs and halons in fire suppression systems and manufacturing processes.
- agricultural activities, including the use of fertilizers, that lead to higher nitrous oxide (N2O) concentrations.