---
title: "James Hansen: 46 Years of Science and Courage"
date: 2013-04-02T01:37:56Z
modified: 2013-04-02T01:38:39Z
permalink: "https://350.org/46-years-science-and-courage/"
type: post
status: publish
excerpt: "Dr. James Hansen, the top climate scientist in the US has just announced his retirement from NASA.\\n\\nHe's been one of the best advocates a planet could ask for -- he even gave us our name when he wrote that 350 parts per million is the safe level of CO2 in the atmosphere. \\n\\n​\\n\\n\\n\\nIf you're on Facebook, please SHARE this image to thank him for his work. \\n\\nAnd then submit a comment to stop Keystone XL in his honor. "
wpid: 30102
author: wpengine
---

Dr. James Hansen, the top climate scientist in the US has just announced his retirement from NASA.

He's been one of the best advocates a planet could ask for — he even gave us our name when he wrote that 350 parts per million is the safe level of CO2 in the atmosphere.

[![](https://s3.amazonaws.com/s3.350.org/images/hansen_thanks.jpg)

](https://www.facebook.com/sharer/sharer.php?u=https://www.facebook.com/photo.php?fbid=10151504824732708&set=a.136077452707.110998.12185972707&type=1)​

[![](https://s3.amazonaws.com/s3.350.org/images/Facebook_share_button.png)

](https://www.facebook.com/sharer/sharer.php?u=https://www.facebook.com/photo.php?fbid=10151504824732708&set=a.136077452707.110998.12185972707&type=1)If you're on Facebook, please [SHARE this image to thank him for his work. ](https://www.facebook.com/sharer/sharer.php?u=https://www.facebook.com/photo.php?fbid=10151504824732708&set=a.136077452707.110998.12185972707&type=1)

[And then submit a comment to stop Keystone XL in his honor. ](https://act.350.org/letter/a_million_strong_against_keystone/)