Amid a depressed global economic environment, investments in cleantech were estimated to total $1.6 billion in the second quarter 2012, down from $1.9 billion in the first quarter 2012and $2.1 billion in the comparable year-ago period (second quarter 2011). Factors driving down investment include global economic uncertainties as well as political opposition to government subsidies in areas such as solar and wind power and electric vehicle development. A depressed U.S. IPO market is further hampering greentech funding efforts.