President Barack Obama's $3.55 trillion budget, released on Thursday, maintains his proposal to reduce carbon dioxide emissions by selling all emission permits to industries. Some members of Congress, including Democrats, are advocating for a portion of the permits to be given away initially to ease the transition to a lower-carbon economy. Critics argue that charging companies for emissions could harm the struggling economy. The plan to sell all permits is expected to generate $646 billion in revenue over the first few years, and the White House budget director confirmed that there would be no changes to this aspect of the budget proposal. During the previous presidential campaign, Obama expressed a desire for all emissions permits to be sold rather than distributed for free, but he has hinted at the possibility of some flexibility on this issue. In Obama's plan, the level of carbon dioxide emissions from various sources would be restricted and companies exceeding the limit would need to purchase emissions credits from those emitting less. The purpose of this cap-and-trade system is to encourage companies to reduce emissions, as emphasized by the director of the Congressional Budget Office during a Senate Finance Committee meeting. David Elmendorf from the CBO explained that giving away allowances is essentially the same as selling them and distributing the proceeds. Elmendorf stated that total revenue generated from auctioning emissions could reach approximately $1.2 trillion over a decade. The increased costs for companies emitting pollutants will lead to higher prices for consumers. In Obama's budget, a portion of the revenues from the cap-and-trade plan is intended to be returned to consumers to help mitigate the price increase. Elmendorf emphasized that a price increase is necessary to encourage a shift in behavior, and while it can be distributed differently, it cannot be avoided entirely. A cap-and-trade bill, sponsored by Representative Henry Waxman, is currently being considered by Congress. Waxman, a California Democrat, is pushing for the bill to be passed by the end of May. However, a senior Republican has suggested that the bill may be delayed while the committee focuses on healthcare reform. This delay could allow Democrats more time to build support for the climate change legislation, according to Representative Joe Barton, a Texas Republican. Some Democrats on the panel, including Mike Doyle of Pennsylvania, believe that most emission permits needed by industry under a cap-and-trade plan will be given away, rather than auctioned, for the first 10 to 15 years of the program. President Obama has expressed a preference for limiting carbon emissions through legislation, but regulation is also an option. The U.S. Environmental Protection Agency stated recently that greenhouse emissions pose a threat to human health and can be regulated as a pollutant.