[1]The legislation would set a cap on total emissions over the 2012–2050 period and would require regulated entities to hold rights, or allowances, to emit greenhouse gases.

Overall net costs would average 0.2 percent of households' after-tax income.The analysis did not attempt to quantify the environmental benefits of reduced greenhouse gas emissions.

That net impact would reflect both the added costs that households experienced because of higher prices and the share of the allowance value that they received in the form of benefit payments, rebates, tax decreases or credits, wages, and returns on their investments."

"[24] The Republicans for Environmental Protection (REP), a national grassroots organization, issued a press release after the vote stating "House passage today of the American Clean Energy and Security Act is a step in the right direction in the fight against dangerous climate change and for developing cleaner, more secure energy resources.

According to an analysis by the Environmental Protection Agency (EPA), the overall economic impact of the cap-and-trade program on household consumption was projected to be modest.

"[27] Economist Paul Krugman argued in favor of the cap-and-trade system, explaining that it creates a financial incentive for companies to reduce emissions by allowing them to sell excess permits.

A report written for The Heritage Foundation, a conservative think tank, on the discussion draft of the bill claimed that the economy would react to this cap-and-trade system like it would lead to an energy crisis.

A Congressional Budget Office (CBO) analysis estimated that the cap-and-trade provisions of the American Clean Energy and Security Act would result in a net economy-wide cost of approximately $22 billion in 2020.

[31] Additionally, the Environmental Protection Agency (EPA) projected that the implementation of the Act would lead to a 0.3% decrease in the Gross Domestic Product (GDP) by 2030.

Additionally, contributors to Yale Environment 360 expressed concerns that the compromises made in the legislation, while politically necessary, could undermine its effectiveness in addressing environmental justice issues.

These compromises were seen as favoring large corporations and potentially leaving low-income households and small businesses at a disadvantage in adapting to the cap-and-trade system.

[34] The Wall Street Journal accused the Congressional Budget Office (CBO) of significantly underestimating the bill's ultimate costs, pointing out supposed flaws in its calculations.

[35] The New York Times reported that the bill's provisions to levy tariffs on Chinese imports due to carbon emissions could provoke a trade war.

The Government Accountability Office (GAO) claimed it was virtually impossible to verify whether carbon offsets represented real emissions reductions.

The Government Accountability Office (GAO) reported that voluntary carbon markets often lack verification systems, making it difficult to confirm whether offsets genuinely reduce emissions.

Additionally, the Energy Policy Institute at the University of Chicago criticized lobbying efforts for shaping the market to favor industry interests, citing the over-allocation of emissions permits and insufficient safeguards against fraud.

[44][45] On June 26, 2009, Reuters reported that "tates" that have set the U.S. agenda on addressing greenhouse gas emissions are lining up behind a federal climate bill, fearing signs of dissent would weaken a plan that still faces hurdles"[46] The article noted that representatives from members of the Eastern U.S. 10-state Regional Greenhouse Gas Initiative, the Midwestern Greenhouse Gas Reduction Accord, which joined six U.S. states with Canada's Manitoba, and the 11-state-and-four Canadian province Western Climate Initiative were supporting the legislation, even though the Eastern market member states, which had already been operating under a cap-and-trade system, "would lose a direct revenue stream of hundreds of millions of dollars if the federal plan were passed".

[46] The National Association of Clean Air Agencies (NACAA) expressed apprehension that the federal cap-and-trade program could preempt more stringent state-level initiatives, potentially hindering aggressive local efforts to combat climate change.

[47] Citizens Against Government Waste named both Reps. Waxman and Markey the May 2009 Porkers of the month for "adding and altering provisions to placate special interests and buy the votes of appropriately skeptical members of Congress".

Dr. James E. Hansen, one of the first to warn about the risks of climate change and an advocate of taking related action, also argued strongly against the bill: 1) It restricted the EPA's ability to regulate CO2 emissions from power plants; 2) it set "meager" targets for emission reductions, with only a 13% reduction by 2020; 3) it lacked certain controls important to the trading of allowances to emit carbon; and 4) it failed to set predictable prices for carbon, making it harder for businesses and households to make investment decisions.

[58] Alternatively, Senators Maria Cantwell and Susan Collins introduced the Carbon Limits and Energy for America's Renewal (CLEAR) Act.

In the months of horse-trading before the vote Friday, the bill's targets for emissions of heat-trapping gases were weakened, its mandate for renewable electricity was scaled back, and incentives for industries were sweetened.

"[53] Business Week emphasized its perceived significance of the legislation and its passage in the House, declaring "June 26, 2009, will go down as an historic moment in world's efforts to tackle climate change.

"[64] It was reported that the passage of ACES in Congress would increase the likelihood that a successor to the Kyoto Protocol would be adopted at the United Nations Climate Change Conference 2009 in Copenhagen.

The Guardian US environment correspondent noted that ACES passing the US House of Representatives "delivers an important boost to the prospects of reaching an agreement for international action on climate change at Copenhagen this year.

"[61] The New York Times noted that "the German chancellor, Angela Merkel, who was in Washington on Friday to meet with Mr. Obama, strongly endorsed the bill even though it fell short of European goals for reducing the emissions of heat-trapping gases.

"[24]This endorsement underscored the urgency of U.S. leadership in global climate efforts, potentially galvanizing commitments from major emitting nations, such as China and India, to adopt stronger emissions reduction targets[65] The bill was offered as a "discussion draft" in the House Committee on Energy and Commerce on March 31, 2009.

Jeff Flake (R-AZ), Alcee Hastings (D-FL), and John Sullivan (R-OK) missed the vote due to "a family conflict", travel abroad in Albania, and "alcohol addiction treatment", respectively.