We will not have arctic ice within 10 years and might not have coral reefs due to global warming, according to Professor of Physics Ken Hayes.
In a three-part lecture series on climate change, Hayes, who has been studying global warming and climate change for 15 years, spoke to Hillsdale College students Feb. 4, Feb. 11, and Feb. 18 about the science behind climate change, the consequences of global warming, and what can be done to change it.
In his first lecture, Hayes began with a comparison of the average temperature of planets without atmosphere to planets with atmosphere. For planets without atmosphere, there is an equation that predicts temperature based on how much radiation from the sun they receive. For planets with atmosphere, the equation is off because atmospheric gases increase surface temperature by redirecting emitted infrared radiation back towards the surface.
“Normally there’s a balance,” Hayes said, explaining that what keeps the earth’s temperature constant is a balance between the sun’s radiation coming in and the earth’s radiation going out. “But we have put a blanket around the earth, and we’ve made it harder for the radiation to exit the ground and get back into space.”
Though the greenhouse gases methane and carbon are only a fraction of the atmosphere, Hayes said, they interact, absorb, and reflect back the infrared radiation from the surface, keeping the earth warm.
“Our problem is that we’ve been adding CO2 to the atmosphere,” Hayes said.
In 1958, Charles Keeling, an American scientist, began precisely measuring CO2 in the atmosphere on the mountain Mauna Loa in Hawaii, and the CO2 was about 315 parts per million. Now it is 410 parts per million.
“We’ve changed the chemistry 46 percent compared to what it was before we started burning coal around 250 years ago,” Hayes said.
The second lecture focused on the impacts of climate change. Hayes explained that the average temperature of the Earth is very sensitive. At the most recent glaciation 20,000 years ago, the Earth’s average temperature was 1.4 percent lower than today, or minus 4 degrees Celsius, and a temperature increase of that four degrees would raise sea levels by 70 meters. Since 1880, the global temperature difference is 1.2 degrees Celsius, all due to CO2 emissions.
“Very few people understand just how much CO2 we’re putting in the atmosphere,” Hayes said. “The world total for 2016 was 36.1 gigatons. The U.S. per capita was 16.1 tons, which is 35,000 pounds per year. That’s almost a 100 pounds per day that we put into the atmosphere.”
In the town of Hillsdale alone, the CO2 emissions per household is 100,000 pounds per year.
The impacts of global warming include ocean warming, surface warming, melting ice, sea level rise, season length, ocean and atmospheric currents, precipitation changes, drought, fire, and the most drastic result – the sixth extinction.
“There have been five major extinctions of life on the planet of all sorts,” Hayes said, “and we happen to be in the sixth one right now, and we’re the cause of the sixth one.”
Already the arctic sea ice is melting so rapidly that it cannot be saved in the next five years, and coral reefs are at risk. In 2016, 70 percent of the Great Barrier Reef was bleached and damaged because of the high temperature of the ocean.
“We’re not going to slow down, we’re not going to stop,” Hayes said. “We are driving the planet towards that sixth extinction.”
Hayes’ third lecture focused on solutions to reducing emissions. Hayes said the Intergovernmental Panel on Climate Change estimated that humans would have to reduce emissions by about 10 percent per year until it reached zero between 2040 and 2055 to stabilize the temperature increase. Hayes pointed to climate scientist Peter Kalmus, who cut his CO2 emissions by 90 percent by biking, not flying, growing his own food, composting, buying fewer items, and going vegetarian. Kalmus’ largest emission was flying – a 19-ton CO2 equivalent in 2010.
“It’s important to find out what your emissions are,” Hayes said, adding that what each individual faces in terms of need varies from region to region.
The problem, especially for industrialized countries, is how to reduce emissions and keep a wealthy lifestyle. Hayes said this can be done with non-CO2 emitting energy technology, such as wind, hydroelectric, and nuclear energy. Changing mode of transportation, like switching from gasoline cars to electric cars, is an example of such technology.
Individuals can act in many ways, including educating themselves, voting for politicians who understand climate change, discussing climate change, and reducing their own carbon footprint.
But in the end, Hayes said, the biggest obstacle to global warming is human nature.
“In principle, it’s pretty simple; in practice, it’s epic,” Hayes said. “The challenging aspect of global warming is getting people to act.”
Sophomore Caleb Ramette said in an email that he was skeptical of the claims on humans causing climate change but that Hayes “presented some convincing evidence indicating that we have at least contributed to global warming” in an unbiased and scientific manner.
“It was concerning to learn that the effects of climate change are delayed, so we might not see temperatures rise until several years after we have caused them,” Ramette said. “Most of the discussions on global warming are politically charged, which means that there are agendas that drive those who deny or support claims on humans’ contributions. It was nice to see actual facts presented to support Dr. Hayes’ claims rather than just hear a list of buzzwords.”
Sophomore Isaac Warchol said in an email that prior to the lecture, he knew that humans were driving climate change, but he didn’t know how quickly the problem was advancing.
“Climate change is an an important issue that does not need to be a strictly political one,” Warchol said. “I think each person needs to reexamine the issue from the standpoint of scientific data and apart from any previous political convictions, and let that information guide their views about their own personal behavior and public policy.”