UBC geographer Simon Donner says that when people saw Typhoon Haiyan crash across the Philippines, they may have asked themselves if climate change caused the storm and high wind speeds.
"Those are questions that are really hard to answer," Donner tells the Straight by phone. "We have a little bit of data saying the strongest typhoons are getting windier."
Donner, who studies ocean temperatures and their effect on hurricanes, says there's a better question: is climate change influencing the effects of extreme weather events like Typhoon Haiyan and Superstorm Sandy, which blasted North America's eastern seaboard last year.
"There, the answer is a pretty clear yes," he says. "You take the same tropical cyclone and you send it toward the Philippines or you send it to New York in the late 1800s and the storm surge won't be be as high."
That's because sea levels are higher in the 21st century. According to Donner, that multiplies the impact of tropical storms and hurricanes on the affected communities.
"The storm surge is much bigger," he says. "That was the issue with Hurricane Sandy....Don't obsess about the storm and the path it took. In 1880, it would not have been that big. It would not have done as much damage."
According to Alan Weisman's recent book Countdown: Our Last Best Hope for a Future on Earth?, a great amount of rice in the Philippines is produced very close to the ocean. That presents risks to the food supply should this land be threatened by storm surges.
A paper on the UN Food and Agriculture Organization website entitled Rice in Southeast Asia: facing risks and vulnerabilities to respond to climate change suggests that this crop is "moderately sensitive to salinity".
There are 5,500 varieties of rice grown in the Philippines.
"However, with the increase in climate change events, farmers are finding it more difficult to maintain rice production levels," the paper states. "They can no longer depend on the seasonal rainfall to irrigate their paddy fields and therefore farmers have to pump groundwater onto the field (about 5,000 litres are needed for 1 kg of rice)."
Rice in the seedling stage is the most sensitive to salinity, with the "symptoms" being "stunted growth, rolling of leaves, white tips, drying of older leaves and grain sterility". Losses can reach 50 percent, and every unit of additional salinity causes a reduction of 12 percent in the yield.
Donner emphasizes that he's no expert on the topography of the Philippines. But he says higher storm surges—as a result of climate change increasing the sea level—will take a toll.
"If you have farmland anywhere near the coast, it's these successive events like this that make the groundwater get saltier and saltier," he says.
Similarly, Donner suggests that storm surges in the Lower Mainland could affect farmland in an area like Delta, which is just one metre above sea level.
"We're never going to be hit by a tropical cyclone," he declares, "but if we have a big weather system come through at the high point of the tidal cycle, you have a little bit of flooding. Over time, those events will make the groundwater saltier and saltier."
He also says there's "general evidence" that if the atmosphere gets warmer, there will be more water in the air.
"And so as the planet warms, we would expect rainfall to get more intense," Donner notes. "That is, in fact, what the data shows. And so that's one of the other big things that does damage during tropical cyclones. You have storm surges, winds, and rainfall....That we do expect to see increasing because of climate change."