Filipino climate experts on Friday, Nov. 26, released a new report, which showed that the Philippines may experience warmer and drier climate in the future due to climate change.

The study titled the "Philippine Climate Extremes Report 2020: Observed and Projected Climate Extremes in the Philippines to Support Informed Decisions on Climate Change Adaptation and Risk Management," outlined the collective findings on historical climate conditions and projected changes in climate extremes in the future.

It is a collective effort of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA), Ateneo de Manila University, and Manila Observatory to provide climate change adaptation planning and disaster risk reduction and management.

Dr. Francia Avila of the Manila Observatory, also one of the study authors, said that the report focused on the projected changes in the climate extremes events which are historically rare but usually have high devastating impacts on the communities.

During the report launch, Avila presented some of the highlights of the Philippine Climate Extremes Report 2020.

Based on the research, Avila said the "extreme temperature indices are all pointing towards a warmer climate for the Philippines as we go further into the future, with the RCP8.5 scenario showing warmer temperature increases than the RCP4.5 scenario."

The RCP or representative concentration pathway is a greenhouse gas concentration trajectory adopted by the Intergovernmental Panel on Climate Change. RCP8.5 is the basis for worst-case climate change scenarios.

"The variations in the change in diurnal temperature range could indicate a larger increase in the daytime temperature and a subsequent increase in the nighttime temperature due to overall heat storage," she said.

Moreover, Avila noted that the fraction of cold days and cold nights are expected to decrease, while the fraction of warm nights and hot days are expected to increase.

"The projected increase in the warm spell duration index is particularly alarming to many sectors of society (e.g. health, energy, agriculture, ecosystem, etc.)," she pointed out.

As regards the projected changes in rainfall, Avila said it varies throughout the Philippines with some areas expected to have increased daily and five-day accumulated rainfall.

"However, the amount of rainfall (on very wet and extremely wet days), number of (very wet and extremely wet days) and the total rainfall from (very wet and extremely wet days), such heavy rainfall days are expected to decrease contributing to a generally dry climate," Avila said.

"The number of continuously wet days is also expected to decrease in the future. And while the number of continuously dry days is expected to decrease, this does not necessarily indicate that sufficient rain would fall during the wet days, which interrupt these dry spells," she said

However, despite the "gloomy" projections, Avila said, "We still do have a bit of time to reduce the impact of future climate extremes."

In the report, the researchers also presented the Climate Extremes Risk Assessment Matrix or CERAM to "help LGUs (local government units) with the planning process," which also provided adaptation options to address the impacts of climate extremes.

Avila said the CERAM will "help LGUs get some headstart in searching for alternative solutions."

The Philippine Climate Extremes Report 2020 is also the third installment of a series of climate change reports produced by the PAGASA.

"PAGASA released the first climate change report in 2011 and it contains information on the observed climate change in the Philippines," Avila said.

"The second report in 2018 contains the observed trends on Philippine climate as well as climate change projections. It also introduced a decision-making tool called CLIRAM or the Climate Risk Assessment Matrix," she also said.

To ensure that the results are robust, Avila said that data from 12 Global Climate Models (GCMs) were downscaled using three Regional Climate Models (RCMs) by different institutions to create a 12-member ensemble of data for the Southeast Asian region.

From this dataset, daily temperature and rainfall data over the Philippines are analyzed.

"Each model has three simulation periods. First, is the historical period which spans from 1971 to 2005, second is the RCP 4.5 projection which spans from 2006 to 2099, and third is the RCP 8.5 projection which also spans from 2006 to 2099," Avila said.

The baseline period is set to 1986 to 2005, coinciding with the available observational gridded dataset.

She said the projected time periods are 2020-2039 for the "early future," 2046-2065 for the "mid-future," and 2080-2099 for the "late-future."