# Drawdown (climate)

Climate drawdown refers to the future point in time when levels of greenhouse gas concentrations in the atmosphere stop climbing and start to steadily decline. Drawdown is a milestone in reversing climate change and eventually reducing global average temperatures. Project Drawdown refers to a nonprofit organization which tries to help the world reach drawdown and stop climate change. In 2017, a publication titled "Drawdown" highlighted and described different solutions and efforts available to help reach this goal.

## Project Drawdown

Project Drawdown is a climate change mitigation project initiated by Paul Hawken and climate activist Amanda Joy Ravenhill.
The Project Drawdown website includes video lessons that explain the analysis and insights behind the efforts and research that make up the science behind the project. The list, which encompasses only technologically viable existing solutions, was compiled by a team of more than 200 scholars, scientists, policymakers, business leaders, and activists. The team measured and modeled each solution's carbon impact through the year 2050, its total and net cost to society, and its total lifetime savings. Below is a table of the top ten solutions included on the organization's website, with the impacts of their respective emissions based on either. The measurements refer to the gigatons of carbon dioxide (CO$_2$) equivalent reduced/sequestered (2020–2050) with the minimum efforts required for the higher goal, and the maximum efforts required for the lower goal.

### Top ten solutions

| Solution | Scenario 1 Min. CO$_2$ -eq (Gt) reduced/sequestered (2020-2050) | Scenario 2 Max. CO$_2$ -eq (Gt) reduced/sequestered (2020-2050) |
| Solution | Scenario 1 Min. CO$_2$ -eq (Gt) reduced/sequestered (2020-2050) | Scenario 2 Max. CO$_2$ -eq (Gt) reduced/sequestered (2020-2050) | Reduce food waste | 87.45 | 94.56 |
| Health and education | 85.42 | 85.42 |
| Plant-rich diets | 65.01 | 91.72 |
| Refrigerant management | 57.75 | 57.75 |
| Tropical forest reforestation | 54.45 | 85.14 |
| Onshore wind turbines | 47.2 | 147.7 |
| Alternative refrigerants | 43.53 | 50.53 |
| Utility-scale solar photovoltaics | 42.32 | 119.13 |
| Improved clean cookstoves | 31.34 | 72.65 |
| Distributed solar photovoltaics | 27.98 | 68.64 |

### Nine Sectors

The interactive website lists nine sectors where immediate action is needed to limit catastrophic climate change. They are:
* Electricity: Electricity production gives rise to 25% of heat-trapping emissions globally.
* Food, Agriculture, and Land Use: Agriculture and forestry activities generate 24% of greenhouse gas emissions worldwide.
* Industry: The industry is directly responsible for 21% of all heat-trapping emissions.
* Transportation: This sector is responsible for 14% of global greenhouse gas emissions.
* Buildings: Buildings produce 6% of heat-trapping emissions worldwide.
* Health and Education: Currently, the human population totals 7.7 billion, and the United Nations estimates that number will grow to between 9.4 billion and 10.1 billion in 2050.
* Land Sinks: While the majority of heat-trapping emissions remain in the atmosphere, land sinks return 26% of human-caused emissions to Earth.
* Coastal and Ocean Sinks: Oceans have absorbed at least 90% of the excess heat generated by recent climate changes and have taken up 20–30% of human-created carbon dioxide.
* Engineered Sinks: The sheer quantity of excess greenhouse gases means that natural processes cannot do it all when it comes to carbon sequestration. Developing technologies show promise to help supplement previously mentioned natural sinks.

## Book

Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming is a 2017 book created, written, and edited by Paul Hawken about climate change mitigation. Other writers include Katharine Wilkinson, and the foreword was written by (hardback edition) Tom Steyer and (paperback) Prince Charles.
The book describes solutions arranged in order by broad categories: energy, food, women and girls, buildings and cities, land use, transport, materials, and "coming attractions". The book provides a list of 100 potential solutions and ranks them by the potential amount of greenhouse gases each could cut, with cost estimates and short descriptions.

### Drawdown Review

A 2020 review of the findings of the research that led to the 2017 book was published as a 104-page PDF in 2020.