The NASA Earth systems science initiative just entered its 20th year, and to mark the occasion, NASA held a symposium at the National Academy of Science to review some of the scientific accomplishments made possible through the endeavor. Over the course of the three day symposium, scientists presented their research and discussed the impact of the NASA earth systems science initiative on the current understanding for a wide range of social, scientific and economic issues.

The size and scope of actions necessary to address climate change can cause paralysis and inaction. In the absence of public policy, emissions would grow to around 60 billion metric tons of carbon dioxide by the middle of this century from current emissions of roughly 30 billion metric tons per year. In order to achieve climate stabilization, most analysis recommends an emission reduction target of 50% to 100% by 2050 from today's levels. Politically, there has been progress. The United States House of Representatives recently passed the climate and energy bill, known as the American Clean Energy and Security Act. The incredible difference between the do-nothing, status quo trajectory and these targets can be daunting. This month on EarthTrends we will give an overview of the most commonly discussed technologies and practices that get us from here to there as well as a consideration of the associated costs of implementing these solutions.

One of the major hurdles to implementing international environmental sustainability objectives is securing local connectivity to, and action for, a global cause. Local communities can struggle in job training, information services support, appropriate policy and legal framework creation, and resource allocation necessary for achieving these goals. Unsurprisingly, this is more likely to occur in developing countries where initiatives are often stumped by spending capabilities and financial allocations.

What may be the largest barrier to connecting communities to international environmental sustainability objectives is cultural integration. Already environmental sustainability is influencing our cultural lifestyle choices, from the food we eat to the way we travel. However, to what extent is it impacting how we are entertained?

The islands of Mauritius and Réunion contain endemic species found nowhere else in the world that are plagued by massive population decline. Before the 1500s, these islands were uninhabited by humans. Soon after the arrival of the first explorers, Dutch settlement and the introduction of non-native plant and animal species, biodiversity loss mushroomed (WRI 1989). Since the over 400 years following the first alterations in the islands' ecosystems, populations of native birds, reptiles, and trees have been driven to extinction.