Iowa officials called on Congress and the next U.S. president to create 2 million new jobs in two years through a $100 billion investment in renewable fuels.

Environmental advocates gathered on the steps of the state Capitol on Saturday amid signs of "We're ready. Green jobs now" to emphasize how Iowa can benefit from growth in renewable energy, such as ethanol and wind power.

The rally, organized by the 1Sky Campaign, was one of more than 660 events held nationwide Saturday as part of an effort to rally the federal government to build an environmentally friendly economy.

About 30 supporters sporting green hard hats stood next to contrasting images of an Iowa wind farm and a smokestack belchng out carbon.

"These jobs will eventually drive our economy and provide much relief to a job market that has seen over 600,000 jobs lost this year alone," Ben Murry, political director of the United Steelworkers in Iowa, said in a press release.

Des Moines Mayor Frank Cownie and Mike Tramontina, the head of the state's economic development department, led the rally along with Andrew Snow of Iowa Global Warming.

Biofuels is an expanding sector of the Iowa economy, which adds $12.7 billion, or about 10 percent, to the state's gross domestic profit, according to the Renewable Fuels Association. Tramontina said that's one of the reasons Iowa's economy hasn't taken a major hit in the current financial climate.

"Iowa is truly a leader in the nation and North America from transitioning from the old fossil fuel-based economy to a new biofuel-based economy," Tramontina said.

The nation's economic slowdown, caused by the collapse of the housing and financial markets and a sharp rise in oil prices, illustrates the need for a large-scale green economic recovery program, Tramontina said.

In Iowa, leaders said a $968-million investment would leave the state with 21,057 new jobs, lowering the unemployment rate to 2.2 percent.

"As the world seeks to reduce greenhouse gases and other forms of pollution, demand for clean, renewable energy will continue to increase rapidly," Snow said.

On Friday, 10 eastern states began selling greenhouse gas pollution credits. Those states have capped their pollution to current levels and plan to begin reducing their emissions to meet a national benchmark.

"It may sound funny, but Iowa's workers may begin helping to clean up New Jersey," Snow said.

Despite skepticism from some, Tramontina said the jobs created from building new wind farms in the state will be sustainable for Iowa's economy.

"Tell me, how sustainable is the wind and the demand for energy? It's not going to end. ... We've got the wind, the work force and the manufacturing capacity to do it," he said.