With Republicans assuming solid majorities in both the Senate and the House, contentious national debates around energy and environmental policy will likely become more visible. They are also likely to be fueled by the competing pressures of increased expectations around global climate talks and oil prices that continue to decline. Here’s a look at some of the flash points and implications:

The Keystone XL pipeline has been cited as a policy priority by GOP leadership, with incoming Senate Majority Leader Mitch McConnell saying it’s his first order of business. The related legislation is expected to pass, but the White House swiftly warned Congress on its first day in session that President Obama would veto it. The measure may be further complicated by a series of unrelated minority amendments or tied to another bill, such as the long-stalled energy efficiency bill first proposed by Senators Jeanne Shaheen (D-NH) and Rob Portman (R-OH) as a bipartisan measure or to a spending package. Such moves could make a presidential veto on the pipeline’s approval harder to justify.

Energy and environment committees in the Senate will now be chaired by Republicans. Energy and Natural Resources will be chaired by Sen. Lisa Murkowski (R-AK), and Environment and Public Works by Sen. James Inhofe (R-OK). Murkowski has identified drilling in the Arctic National Wildlife Refuge (ANWR) as an early focus; Inhofe is widely known for rejecting human influence on climate change. Watch for wrangling between the White House and Congress on major legislation that targets EPA climate regulations, boosts oil and gas drilling, expands natural gas and coal exports, cuts funding to environmental initiatives and reduces tax credits for renewable energy.

Global climate change will be a major component of the international policy landscape in 2015. The next round of negotiations related to a binding rule for countries to abate their greenhouse gas emissions is scheduled for Paris in December; in the wake of recent climate developments between the U.S. and China and the recent climate summit in Lima, an agreement is expected to be reached. Still, such a treaty is unlikely to pass the Senate. There are other hurdles too: conservative pushback could prove to be an obstacle to shaping American public attitudes toward the negotiations, and influential countries such as India are under heavy political pressure to prioritize economic development and alleviate energy poverty over mitigating climate change.

The Obama administration is moving on a number of high-profile environmental regulations, including those governing the use of coal ash and requiring a tighter standard for ozone. Notably, the EPA is writing new climate regulations, with a plan for existing power plants likely to be finalized by summer. Since all federal agencies operate under the authority of the executive office, the new Congressional balance will not directly affect the rules. But they will face legal battles in the coming years, and could be reversed if Americans elect a Republican president in 2016. Indeed, the Supreme Court this spring plans to consider arguments in a suit challenging EPA’s Mercury and Air Toxics Standards.

American financial services, entertainment companies and big-box retailers are not the only organizations grappling with cyber-security; the topic has long been at the forefront of multiple federal agencies with energy oversight, including the Department of Energy, the Defense Department, the Department of Homeland Security and the Federal Energy Regulatory Commission – especially surrounding electric transmission and generation. Given the risks that cyber-attacks pose on the electric grid and other infrastructure, and the crippling consequences of such attacks, regulators and lawmakers are expected to elevate energy-related security protocols in the coming year.

Adam Dolin contributed research to this article.