Last year, the Arctic’s ice cover shrank to the lowest levels in recorded history and, not coincidentally, Royal Dutch Shell Plc (RDSA) received the first permits in decades to begin prospecting for oil and gas in federal waters north of Alaska’s wilderness.

Developers and President Barack Obama’s administration assured us these operations would be safe, thanks to strict oversight and new technology. Now it seems this optimism was misplaced. Unfortunately for Shell and other oil producers seeking to exploit the region, the company’s best efforts were met with multiple failures.

We were open to offshore oil and gas development in the Arctic provided oil companies and the government could impose adequate safeguards, ensure sufficient response capacity and develop a deeper understanding of how oil behaves in ice and freezing water. Now, following a series of mishaps and errors, as well as overwhelming weather conditions, it has become clear that there is no safe and responsible way to drill for oil and gas in the Arctic Ocean.

Read the rest of the letter here.