IN THE 70's and 80's, the strongest typhoons were only Signal No. 3. Today, we have Signal No. 4 and No. 5. Rolly, for instance, was a Signal No. 5 super typhoon with sustained winds reaching 220 km/h. Only two typhoons have so far reached Signal No. 5. The other is Lawin in 2016.
Are typhoons crossing the Philippines becoming stronger? It was in 2015 when the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) modified the public storm warning signal because tropical cyclones have become more intense. Public Storm Warning Signal (PSWS) No. 5 has been added to the storm warning signal.
Is Climate Change to blame for stronger typhoons? I was asked this question when I gave a lecture on Climate Change to high school students at the Angeles University Foundation in Angeles City many years back. My answer was based on basic Science. A typhoon forms when winds blow into areas of the ocean where the water is warm. These winds collect moisture and rise, while colder air moves in below. This creates pressure, which causes the winds to move very quickly.
Since heat is a factor in typhoon formation, I explained (based on common sense) that the hotter the weather, the stronger the typhoon. The hotter weather is due to global warming. My answer proved to be correct. An article in the leading journal Science (Sobel et al. 2016) concludes: " We thus expect tropical cyclone intensities to increase with warming, both on average and at the high end of the scale, so that the strongest future storms will exceed the strength of any in the past."
There was also this study done by researchers at the University of Sheffield, PAG-ASA, the Oscar Lopez Centre for Climate Change Adaptation and Disaster Risk Management (OML Centre). Geographers from the University of Sheffield have analysed annual data over the period from 1951 to 2013 and saw a slightly decreasing trend in the number of smaller cyclones (above 118 kph) that hit land in the Philippines, particularly in the last two decades. More hazardous tropical cyclones (above 150 kph) were shown to be on the increase in recent years, especially in Luzon.
Since we will see more strong typhoons in the future, there is no choice but to adapt. Design of road, buildings, bridges, flood control infrastructures should be based on this new normal. Health care facilities and disaster response plans should likewise be updated. These and all other preparations are contained in the Philippine National Climate Change Action Plan.
Additionally, the proposed Department of Disaster Resilience (DDR) is expected to be approved soon. The DDR shall be the primary government agency responsible for leading, managing, and organizing national efforts to prevent and reduce disaster risks. It would be an institutionalized agency coordinating the national response to disasters and emergencies, replacing the National Disaster Risk Reduction and Management Council (NDRRMC).