Jun. 28--Some environmentalist groups say climate change legislation pending in Congress doesn't go far enough. Some industrial groups say it goes too far. But we're with those who say the legislation provides a good step in the right direction, one that can be built on or adjusted as time goes on.

According to the preponderance of scientific opinion, climate change is here, and human activity is a primary cause. Reversing that course will require leadership from the United States, and that requires leadership from the Obama administration and Congress, leadership that could start with legislation now on the table.

Such legislation would put in place a cap-and-trade system that places a cost on carbon dioxide emissions and other greenhouse gases released into the atmosphere. The system would limit the amount of emissions and then seek to reduce them over time to help keep the concentration of gases in the air from reaching dangerous levels.

Those who argue that the legislation doesn't go far enough are placing the ideal above what's possible now. And what's possible now is the creation of a cap-and-trade system that places a limit on greenhouse gas emissions and then moves toward reducing those emissions.

Those who argue that the bill goes too far are ignoring the reality of what's already happening. The climate is changing, and humans are having an impact on that change. If countries can mitigate that change, so much the better. And while key players such as India and China have yet to sign on to the global effort to reduce the human impact, if the United States sets the course, others may follow.

It's a course most Americans support: According to Environment and Energy Publishing, the Democratic firm Mellman Group and the Republican group Public Opinion Strategies conducted a survey that found that 78 percent of voters still want the United States to reduce greenhouse gas emissions. That number is virtually unchanged since the firms asked that question in March -- prior to the start of the House energy debate -- when 77 percent supported action to reduce emissions.

Additionally, 72 percent of voters support the core principles of the energy legislation that would reduce emissions and force expanded use of renewable energy. Eighteen percent oppose such legislation.

Legislation moving through Congress seeks to reduce emissions to 17 percent percent below 2005 levels by 2020. To do that, it would create a cap-and-trade system in which polluters would be required to obtain credits -- which could be bought and sold -- for the greenhouse gases they produce.