The Philippines has long been vulnerable to weather risks, a fact exacerbated by climate change. Since the 1980s, the growth in agricultural gross value-added (GVA) has been erratic partly owing to the impact of severe weather risks and the periodic occurrence of the El Niño and La Niña phenomena. Aside from typhoons Ondoy and Pepeng, the El Niño in 2010 caused damages to agriculture and fishery estimated at PhP8.4 billion over a total area of 355,986 hectares.
The DOST-PAGASA scenarios for 2020 and 2050 project widespread warming in most parts of the country. Longer hot days and shorter cold days are expected. The number of days with maximum temperature of more than 35 °C is expected to increase in all parts of the country in 2020 and 2050. Projected seasonal mean temperatures in the Philippines are expected to rise by about 0.5-0.9 °C for 2020 and 1.2- 2.0 °C by 2050. Extreme rainfall is also projected to increase in Luzon and the Visayas while a decreasing trend is projected in Mindanao (MDGF-1656, 2010).
These changes bring further pressures on agricultural production, which is already stressed by other resource scarcities and economic challenges. Changing rainfall patterns, rising temperatures, increasing frequency and intensity of typhoons and dry spells, and sea level rise are expected as a result of climate change. These impacts will spell a difference in terms of cropping calendars, unpredictability of yields, pest pressures, crop losses, livestock and fisheries production, and damages to existing infrastructure. Sea level rise is already being experienced in parts of the country, reducing the productive coastal areas for agriculture and fisheries. Salt water intrusion in the lowlands and in aquifers for irrigation and domestic uses is also already being experienced.