CHICAGO (WLS) -- Mayor Rahm Emanuel formally announced Wednesday the city's support of the Paris climate agreement as Chicago welcomed mayors and leaders from around the world for a three-day conference about the global role of cities.The Chicago Council on Global Affairs' gathering seeks to get civic leaders and policy makers to brainstorm on the future influence of cities on the world around us. This year's focus was economics, and the discussion including growing concern about the impact of environmental policy on cities."The decisions we make in the next two to three years will determine what our cities look like in the next 20 to 30 years," Emanuel said as he toured Millenium Park with Toronto's Mayor John Tory.The mayor's support comes after President Donald Trump pulled out of the agreement, but amid municipal leaders vowing to maintain environmental commitments independently."This president, on this policy, is wrong and I will not silence my voice as it relates to the future of the city of Chicago," Emanuel said.Mayors from several cities gathered as part of the larger global affairs event.Tory emphasized their efforts to reduce climate change, but wanted Wednesday to take a closer look at Millennium Park as he is trying to a create a similar attraction in his city which is along the shores of Lake Ontario."Finding and sharing solutions is now our highest priority," said Ivo Daalder, president of the Chicago Council on Global Affairs.And climate change is an area where ideas and solutions could be shared, Emanuel said.Environmental policy advocate Andrew Szwak, of Openlands applauded Emanuel's announcement."There's nothing that climate change does not impact in our natural environment," Szwak said.Szwak said the Chicago area has made strides in cleaning its waterways but damage has been done to the environment, like with the extinction of a species of butterfly. He fears erosion of the climate agreement and EPA funding for the Great Lakes could have long-term impact.The mayor signed the order just under a week after Trump withdrew the United States from the international Paris climate change accord, which is designed to fight climate change and reduce carbon emissions."Chicago has proven you can create jobs while reducing your carbon footprint, and we will continue to do both. As the Trump administration pulls back we will push forward and reduce our fair share of carbon emissions in line with the Paris Accord. The world is depending on cities in the U.S. to take up the mantle of leadership on climate change. Chicago is accepting that challenge," Emanuel said.The executive order commits the city to the goal of reducing citywide greenhouse gas emissions to levels equal to or greater than 26 to 28 percent less than levels in 2005 by 2025, which was the original commitment made by the Obama Administration in the Paris Agreement.In order to meet that goal, the mayor's office will work with sister agencies, environmental advocates, environmental justice groups, community organizations, scientific experts, other cities, state actors and members of the business community on collaborative efforts to collectively reduce Chicago's greenhouse gas emissions.Emanuel said the city has reduced its carbon emissions by 7 percent between 2010 and 2015, while the region's economy grew 12 percent. In April, Emanuel announced all of the city's public buildings will be powered by 100 percent renewable energy by 2025.Emanuel is among the more than 200 mayors nationwide who have pledged to honor the Paris Agreement regardless of the Trump administration's actions.