“We will drill, baby, drill.”

When Professor of Earth Sciences Francine McCarthy heard these words spoken by U.S. President Donald Trump during his inauguration speech, she was stunned.

On Jan. 20, Trump announced a number of measures including the Unleashing American Energy Executive Order, which calls for massive oil, gas and mineral extraction to boost the U.S. economy. Trump also eliminated or revised earlier policies addressing climate change and environmental protections.

Active resource exploration poses further threats to Arctic environments, where melting permafrost dramatically changes landscape and water flows, says Professor of Earth Sciences Martin Head.

“The construction of pipelines, drilling sites and all the infrastructure that needs to go into supporting these activities — and any oil spillage — will have long term consequences for the environment,” he says.

When burned, oil, gas and other fossil fuels release large amounts of carbon dioxide into the air. Carbon dioxide, a primary greenhouse gas, also traps heat in the atmosphere.

“That increased heat energy has to be dissipated somehow,” says McCarthy. “It’s dissipated in more intense storms, more devastating floods, more extreme changes in the climate.”

In their internationally renowned research at Crawford Lake in Milton, Ont., McCarthy, Head and their team uncovered physical evidence of lead, fly ash and other pollutants that continue to be trapped in the annually distinct sediment layers of the lakebed.

While some of these declined in concentration following the enactment of Clean Air legislation in the 1970s, greenhouse gases continue to increase, mainly due to fossil fuel combustion. Deforestation and cement production are also significant sources.

The Crawford Lake site was among locations around the globe showing human activities impacting earth systems so profoundly that scientists worldwide are calling for a new epoch – called the Anthropocene – to be added to the Earth’s geologic time scale.

Head says the Crawford Lake sediment layers document the “Great Acceleration,” a mid-20th century phenomenon associated with global industrialization, commercialization and a significant increase in energy use.

“It’s troubling that the Trump administration is not abiding by the clarion calls from the global scientific community globally that greenhouse gas emissions are leading to bigger problems now and down the road,” says Head of the President’s executive order pulling the U.S. out of the Paris Agreement.

The United Nations’ Paris Agreement, which came into force in 2016, is a legally binding international treaty signed by 194 countries to reduce global greenhouse gas emissions so that the earth’s long-term average temperature doesn’t rise more than 1.5 C above pre-industrial levels.

The U.N. set the 1.5 C limit because anything above that raises the risks of multiple tipping points. On Jan. 10, the journal Nature reported the earth exceeded the 1.5 C limit in 2024.

“Slow changes ramp up and then get faster and faster and become more intense and more devastating,” says McCarthy. “The tipping points suddenly alter how the planet works, how it operates, shifts.”

McCarthy gives the example of the Gulf Stream, a strong current transporting warm water from the Gulf of Mexico into the Atlantic Ocean and up to Northwest Europe. This current regulates temperatures and weather patterns along the North American coast and Europe.

She notes that freshwater flowing into the North Atlantic from a rapidly melting Greenland Ice Sheet is diluting the ocean’s salinity, which is progressively weakening the current.

If the current becomes weak enough and ceases to function the way it’s supposed to, it will result in very cold European temperatures and other major impacts that will be felt around the world, she says.