Secretary of State John Kerry is focusing on climate change, and he is calling on supporters to organize.

The Massachusetts Democrat, in a piece published in USA Today on Tuesday, is urging Americans to increase pressure on congressional members to combat the treat of climate change.

Writing in USA Today, Kerry hearkened back to the 50s, 60s, and 70s, saying mounting concerns during the time forced people to resort to hard work and organize, the only way any change can effectively be pursued.

Calling for a new U.S. energy policy, the one-time presidential candidate said the only way to address the issue is through a more comprehensive and sustainable energy policy focused on efficiency and smart technology. Kerry notes the U.S. should focus on supporting clean energy businesses, and more efficient ways of transporting goods.

“The solution to climate change is staring us in the face. It’s energy policy. If we pursue a global clean energy economy, we can cut dramatically the amount of carbon pollution we emit into the atmosphere and prevent the worst impacts of climate change,” Kerry writes.

Kerry’s piece, published on Earth Day, comes as congressional Republicans continue to fight back against climate change proposals put forth by the Obama administration. President Obama has repeatedly urged congressional Republicans to find a middle ground in pursuing policies that combat the effects of climate change. Nearly 97 percent of scientists now say climate change and global warming are occurring, and a vast majority of scientists say humans are the main source of those omissions.

Writing Tuesday, Kerry said his time in Massachusetts as a young 26-year-old show him the results of joining movements. He noted his time in the state as one of the main organizers for Earth Day.

The Massachusetts Democrat said that nearly 20,000,000 Americans were involved at the time, making it a sustainable and effective means of pursuing energy and environmental policy change. While Kerry said the efforts at the time produce significant results, including the passage and creation of the U.S. Environmental Protection Agency, Kerry said today more substantial measures are needed. The Massachusetts Democrat said a similar effort should be taken in the U.S., in addition to a worldwide movement to cut back emissions in developing countries, such as China and India.

Kerry noted that the world is fundamentally changing, and that nearly 14 of the 15 warmest years on record have occurred since 2000. Last year was the warmest year of all, according to NOAA.