Standing beneath the forest-green peaks of the Sierra Nevada, President Barack Obama drew a connection Wednesday between conservation efforts and stopping global warming, describing the two environmental challenges as inseparably linked.

Obama used the first stop on a two-day conservation tour to try to showcase how federal and local governments can effectively team up to address a local environmental concern like iconic Lake Tahoe, which straddles California and Nevada. Obama told a sunbaked crowd of several thousand in a small lakeside town that “our conservation effort is more critical, more urgent than ever.”

“When we protect our lands, it helps us protect the climate of the future,” Obama said, joined by Senate Democratic leader Harry Reid of Nevada, California Gov. Jerry Brown and Sen. Dianne Feinstein, D-Calif.

Obama’s brief stop along the Nevada-California border came at the start of an 11-day international tour that will take the president to Asia for his final time as president. Throughout the trip, Obama is hoping to elevate issues of climate change and conservation as he works to lock in his environmental legacy.

Addressing leaders of island nations later Wednesday in Honolulu, Obama urged countries large and small to unite behind a common effort on climate and to “row as one,” arguing that no nation can tackle the issue itself.

“When it comes to climate change, there’s a dire possibility of us getting off-course, and we can’t allow that to happen,” Obama said.

The lush island offered Obama a chance to emphasize a theme he’s returned to frequently in his climate campaign: that remote islands are the most vulnerable to rising sea levels and should help lead the fight to slow global warming.

To that end, the president planned an unusual presidential visit Thursday to Midway Atoll, a speck of land halfway between Asia and North America where Obama recently expanded the Papahanaumokuakea Marine National Monument. Then the president heads to China for the Group of 20 major economies summit where climate change is once again expected to be high on the agenda.

In Nevada, Obama paid tribute to picturesque Lake Tahoe, which at 22 miles long and 12 miles wide would cover all of California with more than a foot of water if it were emptied. A major tourist attraction along with the area’s casinos and ski resorts, the lake has been a major source of concern for environmentalists for decades, as underwater visibility began sharply receding.

Senate Democratic leader Harry Reid, who leaves office next year and invited Obama to attend the summit’s 20th anniversary, said thanks to nearly $2 billion in spending since 1997, Lake Tahoe is now “more pristine than it has been in decades.” And California Gov. Jerry Brown, hailing the bipartisan support the lake restoration has enjoyed, called it proof that “beauty transcends politics.”

Scientists believe an array of factors such as storm-water runoff, car traffic and nearby construction have fueled the loss of clarity in the alpine lake, leading to major investments over the last 20 years by Congress, private groups, local authorities and the states of California and Nevada. The latest threat to the lake – warming temperatures that have altered the underwater physics – dovetails with Obama’s emphasis on how America’s most treasured natural wonders are already suffering the consequences of climate change.

Unveiling modest new steps to preserve the lake and its region, the White House said the Interior Department would spend nearly $30 million on wildfire prevention in the area, while other agencies would work on storm-water management, algae monitoring and geothermal energy exploration.

In a veiled swipe at Republicans, Obama mocked those who have questioned whether climate change is occurring or whether humans are to blame.

“You don’t have to be a scientist,” Obama said. “You have to read or listen to scientists to know that the overwhelming body of science shows us that climate change is caused by human activity.”