States, mayors, conservation groups and billionaire Michael Bloomberg on Thursday wasted no time in announcing they would continue pouring energy and money toward combating climate change following President Trump's decision to pull out of the voluntary Paris climate change accord signed at the end of 2015.

The rebellion includes an effort by three of the most aggressive climate mitigation governors from California, New York and Washington. The U.S. Conference of Mayors also joined in the criticism, pledging their cities would continue to work toward reducing the impacts of climate change.

The United States Climate Alliance, a coalition that would commit states to upholding the Paris agreement, was rolled out by Govs. Jerry Brown of California, Andrew Cuomo of New York and Jay Inslee of Washington within hours of Trump's decision. The effort is an offshoot of a similar international effort, the Under2 Coalition, to limit the increase in global average temperatures to below 2 C.

“The president has already said climate change is a hoax, which is the exact opposite of virtually all scientific and worldwide opinion,” Brown said. “I don't believe fighting reality is a good strategy -- not for America, not for anybody. If the president is going to be AWOL in this profoundly important human endeavor, then California and other states will step up.”

Cuomo called Trump's decision to exit the United Nations (UN) agreement "reckless," and said the administration “is abdicating its leadership and taking a backseat to other countries in the global fight against climate change...New York state is committed to meeting the standards set forth in the Paris Accord regardless of Washington’s irresponsible actions."

Inslee said "inaction" by the administration needs to be "met with equal force of action from states. Today’s announcement by the president leaves the full responsibility of climate action on states and cities throughout our nation."

Collectively, California, New York and Washington represent more than one-fifth of U.S. gross domestic product (GDP). The governors reiterated that they are committed to achieving the U.S. goal of reducing emissions 26-28% from 2005 levels and meeting or exceeding the targets of the federal Clean Power Plan.

Meanwhile, Bloomberg said Thursday he would rally a bipartisan coalition of states, cities and business leaders to meet the climate pact's targets.

"Americans are not walking away from the Paris Climate Agreement," Bloomberg said. "Just the opposite; we are forging ahead. Mayors, governors, and business leaders from both political parties are signing on to to a statement of support that we will submit to the UN -- and together, we will reach the emission reduction goals the United States made in Paris in 2015."

Bloomberg, a special UN envoy for mayors and local leaders in meeting the goals of the climate change deal signed by President Obama, also made a $15 million contribution to fund the UN’s climate secretariat, which will lose money under Trump.

"Americans will honor and fulfill the Paris agreement by leading from the bottom up -- and there isn't anything Washington can do to stop us," he said.

The U.S. Conference of Mayors vowed that the nation’s mayors would continue their commitment to reduce greenhouse gas emissions.

“The U.S. Conference of Mayors is a strong proponent of the need to address climate change and we support the Paris agreement, which positions the world’s nations, including the United States, to be energy independent, self-reliant, and resilient,” said Phoenix Mayor Greg Stanton. “A thriving economy and reducing greenhouse gas emissions are compatible by focusing on new technology, investing in renewable fuel sources, and increasing our energy efficiency.”

The Information Technology and Innovation Foundation (ITIF) and a congressional and grassroots coalition, the Millions of Jobs Coalition also lashed out at the president's decision to withdraw from the international accord.

ITIF senior fellow David Hart said the decision by the president was "very discouraging..The United States’ abdication of global leadership will diminish confidence in the pact and discourage other nations from staying the course, while also making it more difficult for the United States to forge robust alliances with other nations on other issues of joint concern.

"But leaving Paris doesn’t mean that all hope is lost. If the Trump administration and Congress focus on innovation, the United States can still be a global leader -- both in the fight against climate change and in the burgeoning market for clean energy."

A Million Jobs coalition spokesperson said the action "will continue to undermine clean energy jobs with his "so-called infrastructure plan that gives huge handouts to his Wall Street billionaire buddies at the expense of investing in clean energy jobs."