This book, and related website ( provide unique guidance on opportunities that are available to reverse greenhouse gas (GHG) emissions with the intent to reverse climate change. Drawdown is intended as a compendium of opportunities, and is not in itself a planning document. This review is intended to suggest how Drawdown may inform climate change planning and policy selection in Ecuador. 

It is important to distinguish solutions that are essentially within the realm of technology, e.g., electric vehicles, and those that rely on government action, changes in behavior (and belief), perhaps even an expansion of awareness of the relationship we have with our planet.

John Porterfield

Founder and partner, Informed Energy Decisions. "" (2003-2008), residential and commercial energy audits through U. of Illinois Smart Energy Design Assistance Center (SEDAC), U. of Illinois. He was the Director of Energy Services for Trade-in Programs at Community Energy Co-op, an initiative of Center for Neighborhood Technology (2000-03). He is the author of How to House Doctor, a 321-page manual providing first systematic instruction in use of infrared scan and blower door to detect residential energy defects. He studied Economics at the University of Missouri at Columbia (1968), and a B.A. in Architecture, U.I.C. (1976)

DRAWDOWN - The Most Comprehensive Plan Ever Proposed to Reverse Global Warming, Paul Hawken, Ed., Penguin Books, April 18, 2017, ISBN-13: 978-0143130444, 256 pages.

How DRAWDOWN is Arranged

For 100 climate change solutions, the book, and the website, compare the outcome of a specified adoption of the solution to a baseline condition.  Drawdown presents:

• Description of the Solution - two pages with photo, some detail of what’s involved, often an acknowledgement of researchers, entrepreneurs, champion of a community or movement having brought the Solution to its current state of development
• CO2 emissions reduction – ranked by gigatons of CO2 equivalent
• Cost – the financial resources that will be required to achieve the potential reduction, forecast for 30 years. In most cases a solution will require financial support, though in a few cases the solution will cost less than the baseline, or “business as usual” condition.
• Operational Savings - both on-going costs and revenue created by the solution, also forecast for 30 years.
• The conditions that yield estimated CO2 reduction, cost and impact are defined.

Solutions are ranked by emissions reduction.  See “Sector Summaries” below for further detail how Drawdown is arranged; but first let’s look at the #1 solution,


Excerpt from the basis for estimates:

IMPACT: Our analysis includes emissions reductions that can be achieved through the management and destruction of refrigerants already in circulation. Over thirty years, containing 87 percent of refrigerants likely to be released could avoid emissions equivalent to 89.7 gigatons of carbon dioxide. Phasing out HFCs per the Kigali accord could avoid additional emissions equivalent to 25 to 78 gigatons of carbon dioxide (not included in the total shown here). The operational costs of refrigerant leak avoidance and destruction are high, resulting in a projected net cost of $903 billion by 2050.

And from the Solution #1 description

Refrigerants, specifically CFCs and HCFCs, were once culprits in depleting the ozone layer. Thanks to the 1987 Montreal Protocol, they have been phased out. HFCs, the primary replacement, spare the ozone layer, but have 1,000 to 9,000 times greater capacity to warm the atmosphere than carbon dioxide.

Because 90 percent of refrigerant emissions happen at end of life, effective disposal of those currently in circulation is essential.

Figures for adjusting the forcing effect of various greenhouse gases in relation to CO2 are well established.  Estimates of GHG reduction must also account for the relative duration that each GHG resides in the atmosphere.  See >

Sector Summaries 

The book is divided into chapters that deal with Sectors.  Information on each sector, found on-line, includes:



primary technologies, and may also include transitional, and enabling technologies

Methodology and Integration

Modeling Methodology
Total Addressable Market
Adoption Scenarios (see Scenarios below)
Sector Integration


Mitigation Impacts – here we find a schematic of the relationship of various types of solutions within the sector, and interactions between the sector and other sectors. Accounting for relationships and interactions is required to avoid “double counting” estimated GHG reduction, cost, etc.

Financial Impacts – here we find a summary of forecast cost and operational savings. Note that Drawdown presents net cost and net operational savings, recognizing avoided costs that deliver a net implementation cost less than the outlay for the solution. Net operational savings may likewise reflect lower recurring costs (e.g., wind as a source of energy rather than fossil fuels), or operational savings may be negative, for instance the cost to contain refrigerant in billions of cooling appliances.

Sector-Level Benchmarks compare Drawdown results with modeling or forecasts from other studies. Comparisons explore whether Drawdown results are reasonable, and help to describe various analyses. 

Conclusions and Limitations

The Sector Summary also includes 


COMING ATTRACTIONS – emerging solutions that would be assigned to the sector

In addition to what is found in Sector Summaries, overall ranking of solutions among all sectors is in a chapter following detail on Sectors and their solutions.

References to Solutions are seen at Also see Errata for corrections to estimates and wording for many Solutions.


Excerpt from the Drawdown website:

Each solution is modeled based on a comparison between a reference case, assuming little change over the next thirty years, and three scenarios reflecting increasingly more accelerated global adoption.

Plausible Scenario: the case in which solutions on the Drawdown list are adopted at a realistically vigorous rate over the period under investigation, adjusting for estimated economic and population growth.

Drawdown Scenario: the case in which the adoption of solutions is optimized to achieve drawdown by 2050.

Optimum Scenario: the case in which solutions achieve their maximum potential, fully replacing conventional technologies and practices within a limited, competitive market.

The data derived from models was then inputted into sector-level integration models to generate final results for all solutions within an in global system.

The Plausible Scenario is forecast 30 years (2047, given this 2017 document).  Note that Scenarios relate to IPCC projections of the carbon budget that will satisfy modeled projections of limiting global warming to less than 2 degrees C.  IPCC Chair Dr. Hoesung Lee presented findings and recommendations in an October Resources For the Future on-line event >


84.6 Gigatons
Reduced Co2
$1.23 Trillion
Net Implemetation Cost
$7.43 Trillion
Net Operational Savings

First, note that WIND TURBINES (OFFSHORE), if combined with WIND TURBINES (ONSHORE) in the ELECTRICITY GENERATION Sector, would rank #1 in GHG reduction. 

In contrast to REFRIGERANT MANAGEMENT, with no given implementation cost, onshore wind turbines have a projected cost based on 20% capacity growth over the past 10 years. An interesting Sector Summary comparison is projected adoption and current adoption. Onshore wind is currently ~4% growing to 22% of generation (plausible scenario). Refrigerant management, capturing gases from equipment at end of life, has no “competing technology.” To achieve the forecast #1 GHG reduction potential will require increasing the current ~3% capture of refrigerant gases to 87%.

Finally, note that REFRIGERANT MANAGEMENT has a negative operational savings, nearly $1 Trillion cost over 30 years, while WIND TURBINES generate savings 6 times that of implementation cost.


Family Planning, ranked #7 at 59.6 Gigatons CO2 reduction, is a policy rather than a technology. Combined with Educating Girls, #6, also 59.6 Gigatons, these policies would easily rank #1. Taking account of the Family Planning correction seen in errata: “The resulting emissions reductions could be 119.2 gigatons of carbon dioxide,” policies addressing conditions of women and girls would provide nearly twice the CO2 reduction of Refrigerant Management.

Planning with DRAWDOWN as a Reference

Realize that Drawdown is a work in progress. Accessing Errata > < one finds changes to the key figures or wording for many solutions. There is a plan to publish detail on modeling, though Drawdown staff may not fulfill the expected 2017 schedule. The effort, though logically having the support of well-established institutions, or government, receives funding as an independent non-profit, and the website lists

As a source of information for planning that is intended to avoid projected unmanageable catastrophic climate change impacts, reliability of information is of concern. Drawdown researchers reviewed more than 5,000 sources, and have listed those sources that were considered in estimating GHG reduction of each solution (and related cost and savings). Estimates are intended to be conservative, and IMPACT often clarifies that a portion of GHG reduction, for example a related reduction benefit that is difficult to quantify, was not included. In addition, each solution (and related cost and savings) accounts for the reduction associated with related solutions with the intent to avoid double counting.

One encounters in scholarly publications a cautionary note that uncertainty in forecasting climate change physics, outcomes of policy, or likely rate of technologic progress is likely less than the uncertainty whether a political decision to proceed with climate reversal work will occur.

The IPCC recommends immediate strong action to transition away from practices that increase GHG gases, with advantages of avoiding unmanageable impacts and costs in lives (and premature deaths), property, public health, adequate nutrition, etc. The economic analysis in Drawdown does not explicitly account for avoided costs in Implementation Cost or Operational Savings. Drawdown does account for economic value of labor in options such as favoring women small-holders in agriculture (ranked #62). As a guide for planning climate change solutions, the type of information provided by Drawdown should be supplemented to account for all costs of various options, those that Drawdown states are not included, and other costs that are not mentioned in this guide.

The estimates of CO2 reduction, cost and operational savings inform the IPCC process of managing global climate change. However, COP21 Intended Nationally Determined Contributions are commitments made by nations. As a planning resource it would be helpful to have Drawdown estimates at the national level. Implementation Cost and Operational Savings that reflect conditions particular to a country are likely required to justify a decision by government or private enterprise to change from the base case to a Solution.

Solutions are shown to have great differences between Implementation Cost and Operational Savings. Selecting Solutions that are appropriate for a nation, and adjusting cost and savings for local conditions, one may “rank” Solutions by ratio of savings to cost. Ranking would help in several ways:

Solutions may offer economic development potential. Ecuador has already realized the potential to expand generating capacity by developing hydropower as an alternative to fossil fuel. Exploring Solutions for their potential economic development value would align with the transition to a sustainable economy.

In some cases, for example refrigerant gas capture, there is perhaps no offsetting revenue or avoided cost that can explicitly offset Operational Cost. Pursuing Solutions that deliver economic benefit may help to justify policies to pursue crucial GHG reduction activities such as refrigerant gas capture.


John Porterfield, Citizens’ Climate Lobby - – 098 164 8719 – 04Dic17 – p 8

Download PDF

Tags: Analysis

Download Free FREE High-quality Joomla! Designs • Premium Joomla 3 Templates