Climate Change Updates

by Alan S. Cajes, PhD

Planet Earth’s greenhouse effect makes life possible by trapping some of the infrared radiation that the Sun emits. It warms the lower atmosphere and the surface of the planet through the greenhouse gases, namely, water vapor (H₂O), carbon dioxide (CO₂), nitrous oxide(N₂O), methane (CH₄), and ozone (O₃). These greenhouse gases absorb and re-radiate the solar heat resulting in a temperature that is conducive for various forms of life[1].

Due to anthropogenic greenhouse gases, however, brought about by human activities over time, the concentration of greenhouse gases in the atmosphere has significantly increased as shown in the picture below. This phenomenon results in “enhanced” greenhouse effect, which leads to global warming and ultimately to climate change. According to the United Nations Environment Programme (UNEP), carbon dioxide is “currently responsible for over 60%” of the enhanced greenhouse effect as a consequence of natural processes and the burning of fossil fuels[2]. The other anthropogenic greenhouse gases come from methane, nitrous oxide, chlorofluorocarbons, CFCs, ozone, etc.

The 2022 report of the Intergovernmental Panel on Climate Change (IPCC) expressed “high confidence” that “human activities are estimated to have caused approximately 1.0°C of global warming above pre-industrial levels, with a likely range of 0.8°C to 1.2°C and that global warming “is likely to reach 1.5°C between 2030 and 2052 if it continues to increase at the current rate[3]”. In the Philippines, the “observed mean temperature anomalies (or departures from the 1971-2000 normal values) during the period 1951 to 2010 indicate an increase of 0.648 °C or an average of 0.0108 °C per year-increase” while the “maximum and minimum temperatures are seen to have increased by 0.36 ºC and 1.0°C, respectively” during the past 60 years[4].

Figure 1. Changes in Global Surface Temperature (Source: IPCC)

According to the Philippine Atmospheric, Geophysical and Atmospheric Services Administration (PAGASA), changes in temperature and the corresponding changes in “rain regimes and patterns” could lead to decreases in crop yield. Less rain, heavy precipitation, and tropical cyclones could severely affect the agriculture sector, especially rice production[5]. Overall, the country “has incurred losses and damages amounting to USD10 billion over the past decade due to climate-related hazards despite contributing only 0.3 percent of the world’s greenhouse gas emissions,” said Secretary Benjamin Diokno of the Department of Finance. He also stressed that “climate change is a daily reality in the Philippines[6]”.

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[1] The greenhouse effect. Retrieved from https://www.bgs.ac.uk/discovering-geology/climate-change/how-does-the-greenhouse-effect-work/ on 21 September 2022.

[2] Climate Change Information Sheet 3. Retrieved from https://unfccc.int/cop3/fccc/climate/fact03.htm on 21 September 2022

[3] Special Report: Global Warming of 1.5ºC. Retrieved from https://www.ipcc.ch/sr15/chapter/spm/ on 21 September 2022.

[4] Climate Trends in the Philippines. Retrieved from https://www.pagasa.dost.gov.ph/information/climate-change-in-the-philippines on 21 September 2022

[5] Climate Trends in the Philippines

[6] Diokno underscores critical role of sustainable finance in climate action. Retrieved from https://www.dof.gov.ph/diokno-underscores-critical-role-of-sustainable-finance-in-climate-action/ on 21 September 2022