Russia, the United States and other countries are hurrying to control Earth's northernmost territory: the Arctic. It is rich in oil and natural gas. The countries want to use these and other natural resources for their citizens and to sell overseas.

Russia has claimed a large part of the Arctic to develop natural resources, including oil. President Barack Obama recently approved proposed drilling in an area under U.S. control. The project was the idea of the Shell Oil Company.

Bill Arnold once worked for the Shell Oil Company. But he now teaches at Rice University in Texas. He just returned home from a fishing trip to Alaska.

"There is no other place that I've ever been that is like this. So I am very interested in the preservation of the beauty of Alaska."

Mr. Arnold said he believes that new energy resources can be developed without harming nature.

But many environmentalists disagree. They denounce U.S. oil company projects in the Arctic, and they are not satisfied with President Obama's decision.

The Arctic has become more accessible because polar ice is melting much faster now than in centuries past. Many scientists point to climate change as the reason behind the melting ice. Climate change, they say, results from the use of fossil fuels, like petroleum oil for cars and other vehicles.

Professor Arnold says studies have shown the Arctic has plenty of oil.

"Probably something like 25 percent of the undiscovered oil and (natural) gas in the world is in the Arctic."

Half of the Arctic lies next to Russian territory. Russia sees the Arctic as important for its own energy production.

"I think their view is that as the traditional resources are dwindling, they need to find new resources and some of the greatest resources in the world are in that area."

Russian development of the Arctic slowed after Western nations ordered sanctions against Russia. The sanctions were meant to punish Russia for taking the Crimea from neighboring Ukraine. Western-based companies were forced to withdraw from partnerships with Russia.

But Mr. Arnold says the opening of the Arctic raises other concerns. He says Russia has a major military presence in the area. The United States, he points out, has a much smaller presence in the Arctic.

He also says many countries are developing shipping projects through Arctic waters once the ice is unblocked.

"The potential of it is really untested and unknown at this point. But to be able to have that kind of circumnavigation in a relatively tight range in that area could be profoundly important."

Mr. Arnold says it could be some time before Shell's explorations affect U.S. energy production. He says it will be seven to 10 years before those efforts begin to pay off with large-scale production.