Prior to becoming Opposition Leader, Abbott initially supported proposals by Liberal leaders Howard and Turnbull to introduce floating prices to reduce carbon emissions, but also expressed some doubts as to the science and economics underlying such initiatives. In 2009, Abbott announced his opposition to Turnbull's support for the Rudd Government's Emissions Trading Scheme proposal, and successfully challenged Turnbull for the Liberal leadership, chiefly over this issue. As Opposition Leader, Abbott declared that he accepted that climate change was real and that humans were having an impact on it, but rejected carbon pricing as a means to address the issue, proposing instead to match the Labor government's 5% emissions reduction target through implementation of a plan involving financial incentives for emissions reductions by industry, and support for carbon storage in soils and expanded forests. On the eve of the 2013 Election, Abbott told the ABC: