Mongabay: Now that Barack Obama has been president for nearly two months, it is time for him to give a defining speech on climate change. While Obama has spent most of his time on what the majority of Americans consider the most pressing issue–the economy–he has proven himself adept at juggling the economy with other vital issues. A fact-based speech on climate change would accomplish several goals. First, by using his unique position in the world, Barack Obama could directly impact the …