It's in the shadow of Copenhagen, but Obama's first trip to China could prove to be a real turning point in climate legislation.Last week, the leaders of the world's two largest greenhouse gas polluters had a historic meeting that should someday be remembered as a turning point in our global climate challenge. You could be forgiven for missing the story as it happened. The timing of President Obama's meeting with Chinese President Hu Jintao, a few short weeks before the potentially-even-more-historic meetings in Copenhagen, overshadowed and colored the coverage. Many of us-and I certainly include myself-were hoping (against rational hope) for a game-changing announcement in Beijing that would jump start the stalling UN talks. As we poured through the Joint Statement released by the two nations, I think many saw the lack of such an obvious catalyst as a missed opportunity.Meanwhile, the two countries that together are responsible for 40 percent of global greenhouse gas emissions announced a "positive, cooperative, and comprehensive" plan for collaboration on clean energy, and taking a close look at the measures therein, there's an awful lot in there to be excited about. Here's a quick run-down of the joint efforts soon-to-be underway:• U.S.-China Clean Energy Research Center: With at least $150 million for the next five years, the US-China CERC will fund teams of scientists and engineers from both countries to research crucial carbon-reduction technologies, starting with building efficiency, carbon capture and storage (before you moan, see the 21st Century Coal note below), and clean vehicles, and will also serve as a clearinghouse to help other researchers in both countries. [Fact sheet pdf]• U.S.-China Electric Vehicles Initiative: As the world's two largest automobile markets, the US and China will work together to accelerate EV technological development and to eliminate barriers to more widespread EV use. [Fact sheet pdf]• U.S.-China Energy Efficiency Action Plan: Under this plan, the two countries will "work together to improve the energy efficiency of buildings, industrial facilities, and consumer appliances," through the development of building codes and ratings standards, training programs for buildings inspectors and energy auditors, and by facilitating the sharing of best practices between industries and cities through an annual U.S.-China Energy Efficiency Forum and a Mayors Sustainable Cities Program. [Fact sheet pdf]• U.S.-China Renewable Energy Partnership: The Partnership will develop joint "roadmaps" for the widespread deployment of clean, renewable energy in both countries, also providing technical resources to states and regions within each country to help rapidly bring massive volumes of clean energy online. Also, as the official fact sheet notes, "given the combined market size of the U.S. and China, accelerated deployment of renewable energy in the two countries can significantly reduce the cost of these technologies globally." [Fact sheet pdf]• 21st Century Coal: The leaders pledged to "promote cooperation on cleaner uses of coal, including large-scale carbon capture and storage (CCS) demonstration projects." Of course, avoiding the combustion of fossil fuels is the best approach, the energy and economic realities of China are such that an enormous amount of coal is going to be burned. CCS for China is undeniably essential in avoiding catastrophic climate change, and the faster it's ready and economically viable, the better. [Fact sheet pdf]• Shale Gas Initiative: Using "experience gained in the United States to assess China's shale gas potential," this initiative will work to "promote environmentally-sustainable development of shale gas resources." Not quite as controversial as CCS, but certainly no environmental dream-come-true, shale gas could serve an important role as a bridge, easily replacing coal to meet energy needs while building baseload capacity of true clean energy sources. [Fact sheet pdf]• U.S.-China Energy Cooperation Program: The ECP will "leverage private sector resources for project development work in China across a broad array of clean energy projects, to the benefit of both nations." Over 22 companies (no word yet on who they are) have signed on as founding members, and collaborative projects will focus on renewable energy, smart grid, transportation, green building, clean coal, combined heat and power, and energy efficiency.On top of all these measures, the "disappointing" Joint Statement I mentioned earlier, while lacking any direct, immediate impact on the Copenhagen talks, did include some "subtle, but important shifts in global warming positions," as NRDC's Jake Schmidt described them. Regarding the nature of the Copenhagen agreement, the countries emphasize that "while striving for final legal agreement, an agreed outcome at Copenhagen should...include emission reduction targets of developed countries and nationally appropriate mitigation actions of developing countries." (Emphasis mine.) As I've mentioned time and time again, the biggest roadblock to progress in these United Nations talks has been America's hesitation to put mitigation and finance numbers on the table. This statement would seem to make absolutely clear that the United States will talk targets in Copenhagen.On the other side, China's reluctance to "open up their books and defend them"-or to agree to some standardized form of measurement, reporting, and verification of emissions reductions-has long been a major sticking point. Well, according to the Statement, the two countries "resolve to take significant mitigation actions" and "resolve to stand behind these commitments," while also "providing for full transparency with respect to the implementation of mitigation measures." (Emphasis again mine.)"This is bold language for China," write Julian Wong and Andrew Light of the Center for American Progress. "It is now clear that China is signaling its increasing willingness to meet the standards of transparency, accountability, and verification that will be necessary to create an acceptable global agreement on climate change. This will be critical to reassure skeptics of domestic climate pollution legislation in the United States that China will keep any promises it makes to reduce its carbon emissions."So even without the bold, headline-making announcements that so many climate activists were holding out for, these signals undeniably mean good things for Copenhagen. And the measures laid out for cooperation on clean energy between the world's two largest fossil-fueled economies should ultimately prove Obama's first trip to China to be a true climate turning point.