Scientists for years have warned that climate change will destroy the natural world, but many have been hard-pressed to prove it. Today, a 30-year-old theory begins to shed light on climate change by looking at the past ice age and its effect on the earth.
The theory was developed by Professor Dick Peltier of the department of planetary physics at U of T, who has charted the way the earth moves for most of his life. He is this year’s recipient of the Miroslaw Romanowski Medal given by the Royal Society of Canada for his work in advancing climate change research.
“On very, very long time scales, solid earth behaves like silly putty,” he explained. “If you keep pushing it, it flows like liquid.”
The effect, which forms the basis of Peltier’s research, is termed the earth’s viscosity and is best observed by studying the response of the planet to ice ages. The last glaciation had covered Canada with a 2 km-thick sheet of ice that has weighed the earth down such that continents are still responding today. Like a spring, sea level in places like Hudson Bay has been falling because the earth underneath is rising from the alleviated weight of deglaciation. These measurements allow Peltier to observe the earth’s viscosity and patterns of continental drift in the past 21, 000 years.
“This is right at the heart of all the debates which are going on about climate change,” Peltier said.
Sea level changes, the earth’s movement, and the fluid-convection system of the atmosphere are all closely related phenomena that form Peltier’s greater theory on climate change. Significant fluctuations in the system of climate and continent interactions have prompted the theory into a simulation model of climate for the entire world.
“There’s an ancient ice age effect [on sea level] and then a modern global warming effect associated with greenhouse gases in the atmosphere,” Peltier said. “The work I have done enables you to pick those two parts apart.”
The global climate model simulation accurately predicts sea level at any given point in the world as a consequence of the last deglaciation event and earth’s memory of it.
“This is very important in understanding the additional effect on sea level that’s associated with greenhouse gas-induced global warming,” Peltier said. First-hand measurements made by a tide gauge at any coastline in the world can be compared to Peltier’s predictions, meaning more accurate conclusions about global warming can be made.
By identifying the cause of atmospheric anomalies, be it deglaciation or human civilization, Peltier’s research lays the groundwork for targeting causes and stabilizing our changing climate. His simulation model, used internationally by researchers, is an important tool in understanding today’s changing world.
