Throughout his presidency, Trump reversed several American commitments to mitigating climate change that were made during the Obama administration -- most notably pulling out of the Paris Agreement, removing clean water protections and seeking to fast-track environmental reviews of dozens of major energy and infrastructure projects, such as drilling, fuel pipelines and wind farms.
After Biden was sworn in as the 46th president on Jan. 20, he was ready with pen in hand to begin signing executive actions -- 33 in less than a week, with nearly two dozen of them aimed specifically at undoing what was on Trump's agenda.
Biden appointed former Secretary of State John Kerry as climate envoy, a role that holds authority over energy and climate policy within the executive branch as well as former EPA administrator Gina McCarthy as White House climate adviser.
Here are the environmental actions Biden has taken so far:
Biden signs sweeping executive orders on climate change, the environment
On what the White House described as "Climate Day," Biden signed a sweeping executive orders on policies to protect the environmental and mitigate rising temperatures.
"In my view, we've already waited too long to deal with this climate crisis. We can't wait any longer," Biden during a briefing on Jan. 27. "We see it with our own eyes. We feel it. We know it in our bones. And it's time to act."
The order aims to tackle the climate crisis both domestically and internationally as well as create jobs and a clean energy future, build modern and sustainable infrastructure and restore "scientific integrity and evidence-based policymaking across the federal government," according to the White House.
The executive orders will encompass a wide range of environmental concerns, such as climate change, clean energy and protection of land and ocean.
Biden emphasized that "climate day" also means "jobs day" as well, saying that innovation, products and labor created during the climate fight will also create jobs.
The climate plans will create 1.5 million new energy-efficient homes, 1 million new jobs in the automobile industry, 500,000 new electric vehicle charging stations and 250,000 jobs for things like plug millions of abandoned oil and gas wells, Biden said.
Biden added that Trump vowed to save the jobs of "forgotten" men and woman during his presidency but eventually abandoned them for the big oil industry.
"And when the previous administration reversed the Obama-Biden vehicle standard and picked big oil companies over American workers, the Biden-Harris administration will not only bring those standards back, we’ll set new ambitious ones that our workers are ready to meet," Biden said.
The new president acknowledged the large scale of the executive order, but emphasized that it can be done.
"Our plans are ambitious, but we are America. We're bold," Biden said of the new climate agenda.
The U.S. reentered the Paris Agreement
Biden kept his promise to rejoin the Paris Agreement -- the accord among nearly every country in the world to prevent the earth's temperatures from rising -- the day he entered office.
Trump announced his intention to withdraw from the agreement in 2017, claiming it could be economically detrimental and cost 2.5 million Americans their jobs by 2025. The U.S. officially left the accord on Nov. 4, the day after Election Day.
Re-entering the agreement was among one of the first actions Biden signed upon arriving to the Oval Office.
Environmental policy experts told ABC News last year that while the U.S. lost its standing as a climate leader under Trump, it would take more than simply reentering the global stage for it to regain that status -- that it would have to keep ambitious commitments for reducing its greenhouse gas outputs.
Permits for the Keystone Pipeline were revoked
Construction on the TransCanada Corporation Keystone XL oil pipeline has halted after the permits were revoked by Biden during his first day in office.
The 1,700-mile project, slated to carry about 800,000 barrels of oil per day from Alberta to the Gulf Coast in Texas, was first proposed under President George W. Bush but was later stopped by the Obama administration, which cited potential pollution concerns.
One of Trump's first big moves as president was overturning Obama's decision and signing an executive order to approve the development, stating it would benefit the economy.
"The Keystone XL pipeline disserves the U.S. national interest," the Biden executive order states. "The United States and the world face a climate crisis. That crisis must be met with action on a scale and at a speed commensurate with the need to avoid setting the world on a dangerous, potentially catastrophic, climate trajectory."
The halt will eliminate more than 1,000 jobs in the upcoming weeks, said Keystone XL President Richard Prior.
On Monday, Canadian Prime Minister Justin Trudeau expressed "disappointment" over rescinding the permit during a call with Biden, according to the White House. Trudeau had previously announced his support of the project in 2018.
ABC News' Ben Gittleson, Sarah Kolinovsky and Christine Theodorou contributed to this report.