"For this fall," Mr. Katz wrote in his e-mail to Mr. Hansen, "we are hoping to host a debate on global climate change and its implications. Patrick Michaels has agreed to come, and my organization would like you to come and debate Dr. Michaels in Williamsburg. The date is very flexible, and we can tailor the day of the debate completely to your schedule. We will be able to pay for your travel expenses and offer you an honorarium for your time. Please let me know if you would be interested."