Reuters: The top U.S. climate change official brought a “message of hope” to a summit of environment ministers from rich and poor nations on Wednesday, saying Washington was committed to curbing greenhouse gases. Lisa Jackson, head of the U.S. Environmental Protection Agency (EPA), told the Group of Eight (G8) industrial countries and major developing nations that U.S. President Barack Obama was willing to work tirelessly toward a deal on global warming. “I bring from President Obama …