<p>The top concern of Unites States businesses for climate change and environmental issues is reducing carbon emissions, according to PricewaterhouseCooper&#39;s Appetite for Change global survey. United States survey respondents ranked reduction of carbon-dioxide emissions as the issue to most impact their companies over the next two to five years (16 percent), followed by new regulation, (13 percent), energy efficiency (12 percent), and legislation/new laws (11 percent).</p>