Republicans have questioned Obama's focus, saying there has been little to show for all the money spent. They point to boondoggles like the administration's decision to pump $528 million into California solar company Solyndra before it collapsed, laying off 1,100 workers.

The report makes no assessment of when the jobs were created and says its figures are from 2010. It found 2.3 million green jobs in the private sector and 860,300 in the public sector.

In the private sector, manufacturing had the greatest number of green jobs with about 461,800, about 4 percent of all manufacturing employment. Construction was second, with about 372,000 jobs.

Vermont had the highest proportion of green employment at 4.4 percent, while Florida had the lowest at 1.3 percent. California had the largest number of green jobs, with 338,000 workers.

But the report is sure to add to the debate over how exactly to define green jobs. Some may wonder how the report can say nuclear power plant employees have green jobs, but not workers who make bicycles.

The answer lies in a two-part definition that the BLS developed in 2010. The first part counts "output-based jobs" that produce goods and services benefiting the environment or conserving natural resources. That includes a company producing solar panels or a farmer growing organic tomatoes.

The second part of the definition covers "process-based jobs" where workers make a company more environmentally friendly or use fewer natural resources. That would include an employee at a manufacturing plant in charge of recycling, even if the plant itself is not green.

A nuclear power plant is green because it produces energy without causing harmful greenhouse cases, said Rick Clayton, chief of the division of administrative statistics and labor turnover at BLS. The agency ignores the fact that nuclear power produces radioactive waste that may have longer-term impact. But the process of manufacturing a bike does not benefit the environment, even though someone who later rides the bike instead of driving helps keep the air clean, Clayton said.

The report released Thursday includes only jobs under the first part of the definition. A second report counting process-based green jobs will be released later this year.

Clayton said coming up with an accurate count of green jobs was tricky because not every step of producing and delivering a green product is environmentally friendly.

An organic tomato, for example, helps the environment benefit where it's grown, Clayton said. But the process of being canned and then delivered by truck to a restaurant has no benefit to the environment, he said.

"To think that we could track an organic tomato would make the definition too broad and it would be uncollectible," Clayton said.

The BLS surveyed 333 industries out of 1,193, and excluded those industries that have no primary environmental benefit, Clayton said.

Clayton said the BLS report is consistent with a 2010 report from the Commerce Department which came up with its own definition to find the number of green jobs in the private sector ranged from about 1.8 million to 2.4 million.

Obama's Council of Economic Advisers has claimed that about 225,000 green jobs were saved or created through the first nine months of 2010. That figure is not verifiable in the latest report.