[2] The 350 in the name stands for 350 parts per million (ppm) of carbon dioxide (CO2),[3] which has been identified as a safe upper limit to avoid a climate tipping point.

"[9] 350.org states their demand as the following "We want institutions to immediately freeze any new investment in fossil fuel companies and divest from direct ownership and any commingled funds that include fossil-fuel public equities and corporate bonds."

[10] 350.org named the Keystone XL pipeline as a critical issue and turning point for the environmental movement, as well as for then-President Barack Obama's legacy.

[12] 350.org has opposed the economic argument that has been made by proponents of the pipeline, arguing that Keystone XL would create only a few thousand temporary jobs during construction.

[13] Additionally, the Natural Resources Defense Council (NRDC) has said that the Keystone XL pipeline will increase gas prices instead of lowering them as oil industry proponents claimed.

That gives him new stature as an environmental leader, and it eloquently confirms the five years and millions of hours of work that people of every kind put into this fight.

[24] The actions organized by 350.org included gigantic depictions of the number "350",[25][26] walks,[27][28] marches, rallies, teach-ins, bike rides, sing-a-thons, carbon-free dinners, retrofitting houses to save energy,[29] tree plantings,[30] mass dives at the Great Barrier Reef, solar-cooked bake-outs, church bell ringings, underwater cabinet meetings (Maldives),[31][32] and armband distributions to athletes.

Actions from tree-plantings to solar panel installations to huge electricity service-provider switching parties occurred in almost every country around the world.

[42][43][44] The organization's efforts continued into 2012 with a planned May 5 worldwide series of rallies under the slogan "Connect the Dots" to draw attention to the links between climate change and extreme weather.

[47][48] Phase 1 of Global Power Shift was a convergence in Istanbul, Turkey, in June 2013 of about five-hundred climate organizers from 135 countries.

These activities include tree plantings (350 trees in each instance) for biosequestration,[54][55][56][57][58][59] promoting the term "350",[60][61][62][63][64] publishing adverts in major newspapers calling for the target level of carbon dioxide to be lowered to 350 ppm,[65] conducting polls on the subject of climate change,[66][67] educating youth leaders,[68][69] lobbying governments on the issue of carbon targets,[70] and joining a campaign to establish a .eco top-level domain or "tld".

[72] The organization created and distributed a time-lapse video showing the recent retreat of Mendenhall Glacier in Alaska, graphically depicting the impacts of warming climates.

We're also creatures of emotion, intuition, spark – which is perhaps why we should mount more poetry expeditions, put more musicians on dying reefs, make sure that novelists can feel the licking heat of wildfire.

McKibben credits these activities with making Hillary Clinton and Barack Obama change their energy policies during the 2008 United States presidential campaign.

McKibben is an American environmentalist and writer who wrote one of the first books on global warming for the general public, and frequently writes about climate change, alternative energy, and the need for more localized economies.

[83][84][85] McKibben promotes the organization on speaking tours and by writing articles about it for many major newspapers and media, such as the Los Angeles Times[86] and The Guardian.

[90] In May 2013, two independent teams of scientists measuring CO2 near the summit of Mauna Loa in Hawaii recorded that the amount of carbon dioxide in the atmosphere exceeded 400 ppm, probably for the first time in more than 3 million years of Earth history.

This was reaffirmed in the 2018 report by the Intergovernmental Panel on Climate Change, where the world's leading scientists urged action to limit warming to 1.5 °C.

Fossil-fuel companies have about 2,795 gigatons of carbon already contained in their proven coal and oil and gas reserves, and is the amount of fossil fuels they are currently planning to burn.

[94][95] Many notable figures have publicly allied themselves with the organization or its goal to spread the movement,[29][96] including Archbishop Desmond Tutu, Alex Steffen,[97][98] Bianca Jagger, David Suzuki, and Colin Beavan.