Snow cover, temperature fluctuations pose climate threat
Despite the endless bombardment of snow in the New Brunswick area, there is an observable long-term warming occurring on Earth that affects all of its inhabitants.
The weather in New Brunswick is unpredictable more than a week in advance, but global trends allow for discussion of how the climate will change over the next few years.
Anthony Broccoli, co-director of the Rutgers Climate Institute, said January was in the top 20 coldest months in over 100 years, but there have been colder winters.
While this January was colder than average, there has been a trend for warmer weather throughout the past decade, said Broccoli, a professor in the Department of Environmental Sciences.
This long-term trend is apparent in temperature rankings, he said. Since 2000, there have been many more months reaching record high temperatures than low.
“We pay a lot of attention to what’s happening where we live,” Broccoli said. “This January was unusually cold. … But there are many places where it’s been unusually warm this winter.”
Steven Decker, an instructor in the Department of Environmental Sciences, said that California is continuing to experience drought problems, and temperatures in Alaska have been reaching record highs.
“It’s easy to look out at your backyard and see the snow and not remember those warm winters,” he said.
After this particularly snowy winter passes, Decker said that the snow on the ground might mean a slower, colder start to spring.
“In the spring, the sun heats up the ground, and the ground heats up the air,” he said. “As long as there’s snow on the ground, that’s not going to happen.”
Decker said the snow also reflects a lot of sunshine instead of absorbing the sun’s energy, which means it takes a long time for the snow to melt.
The fluctuations in temperature this winter are not rare, although they are more frequent than usual, Broccoli said.
The increase in fluctuations may be due to the melting sea ice in the Arctic, he said, but it is too soon to tell for sure.
“The winds that blow across North America in the winter occur, because there is a contrast between the warmer temperatures in the tropics and the colder conditions in the polar regions,” Broccoli said.
The melting sea ice has caused the Arctic region to experience warmer temperatures, which may have disrupted the air circulation in the atmosphere, he said.
“What makes it hard to know whether or not this is correct is that there are large fluctuations in the winters normally,” he said. “We need a lot of years of observation to see if there’s a trend developing.”
The increasing fluctuations in temperature pose problems for plant life, said Bruce Clarke, chairman of the Department of Plant Biology and Pathology.
Plants go into a dormant state in the winter that is caused by the decrease in regional temperatures, he said.
“This kind of winter is not nearly as bad as a warm winter,” Clarke said.
He said that fruit-bearing plants start to blossom in response to warm temperatures. If freezing temperatures follow warm conditions, the blossoms will die.
“You can even see flower buds come out in January sometimes, and then it gets cold again. That’s the really destructive part. Plants come out of dormancy too early and they’re not protected,” he said.
The temperature fluctuations also allow ice cover to form, he said. Warm days cause the snow to melt, and the cold days that follow freeze the water into ice.
“The biggest concern is not persistent snow cover. It’s persistent ice cover,” he said.
He said when ice forms over the ground and within the soil, that impermeable layer stops the plants from getting the oxygen they need.
“The snow melts, then it saturates the soil, and then it freezes again,” he said. “It’s the layer of ice that’s the worst thing.”
While the temperature fluctuations cause problems, the plants have no issue with the abundant snowfall.
“Snow is usually a good thing for plants. It acts as an insulating blanket,” Clarke said. “For example, if we get a blast of cold air, the snow covering the plants acts as a buffer for that exceptionally cold weather.”
Clarke said this winter’s temperatures with no snow cover would be particularly damaging to plants. The snow cover also protects plants from the temperature fluctuations, since it keeps the ground at a constant, cold temperature, he said.
Cesar Rodriguez-Saona, associate extension specialist in the Department of Entomology, said the weather has been inviting new invasive pests — the brown marmorated stink bug and the spotted wing drosophila are examples of these new pests.
While Rodriguez-Saona said he is confident that both these species came from Asia, the exact range of their native regions and the climates to which they are adapted are unconfirmed.
“I know the range of the brown stink bug is fairly large, and we are finding the spotted wing drosophila as far north as Canada, so we know that they can survive temperatures that are below freezing,” he said.
To survive the winter, insects go into an overwintering state. During this process, Rodriguez-Saona said many insects produce compounds like glycol that act as an anti-freeze for cells. Many slow down their metabolism and do not feed.
Rodriguez-Saona said if invasive pests are not adapted to survive the cold winter, they can migrate to warmer temperatures, and new populations come to this region from the south every year.
Even if the cold weather does cause a dramatic decrease in insect populations, it may not cause the species to suffer.
With the unusual cold, plant breeders are hopeful that the population of destructive insects from warmer climates might suffer, Clarke said.