By C. Forbes Tompkins, Kelly Levin and Noah Kaufman

During the recent confirmation hearings of President Trump's cabinet nominees, a familiar pattern has emerged. Many of them have acknowledged that climate change is happening, but each has then sowed doubt by either understating the connection between human activity and climate change or by suggesting that there's too much uncertainty to act. The overall effect of these statements is to confuse or stall progress.

The reality is that we know plenty about the role of people as a primary driver of climate change and government officials certainly know more than enough to act.

For example, during his hearing to become the U.S. Environmental Protection Agency (EPA) administrator, Scott Pruitt claimed: "There is a diverse range of views regarding the key drivers of our changing climate among scientists."

Rex Tillerson, President Trump's selection to become the next Secretary of State, remarked: "I agree with the consensus view that combustion of fossil fuels is a leading cause for increased concentrations of greenhouse gases in the atmosphere. I understand these gases to be a factor in rising temperatures, but I do not believe the scientific consensus supports their characterization as the 'key' factor."

Simply put, these views are not accurate and fly in the face of well-established science. The underlying research showing the connection between increasing CO2 concentrations and a warming planet was established more than 150 years ago. The statements above conflict with conclusions from all leading national and international scientific institutions (IPCC, NCA, WMO, NAS and UK MET Office) and they contradict the findings of the departments and agencies these appointees may soon be leading.

It is time for these leaders to look carefully at the climate science and establish policies based on the best scientific information available.

Here's a brief reminder of some of our fundamental understanding about climate science:

1. Global Temperatures are Rising at Unprecedented Levels

• 2016 was the third consecutive year of record-warm global average temperatures.

• 16 of the 17 warmest years on record have occurred this century.

• Average global temperatures have been above the 20th-century average for the past 40 consecutive years.

• Since 1880, global temperatures have risen by more than 1 C (1.8 F), while levels of carbon dioxide in the atmosphere have increased from 280 parts per million (ppm) to more than 400ppm.