Climate-Safe California Scientific Citations


Ripple, et al. World Scientists’ Warning of a Climate EmergencyBioScience, Volume 70, Issue 1, Jan 2020; IPCC 2018

Lenton, et al. Climate tipping points — too risky to bet against: The growing threat of abrupt and irreversible climate changes must compel political and economic action on emissions. Nature. Nov 27, 2019

ScienceDaily, Nine climate tipping points now ‘active,’ warn scientists Nov 27, 2019

Global Risks Report 2020: A decade left: Confronting Runaway Climate Threat. World Economic Forum. Jan 15 2020

Dangers of Accelerated Biodiversity Loss in Global Risks Report 2020. World Economic Forum. Jan 15 2020

Leleiveld et al., Loss of life expectancy from air pollution: a worldwide perspectiveCardiovascular Research, March 2020

Hoffman et al. Effects of Historical Housing Policies on Resident Exposure to Intra-Urban Heat. Climate, 2020

K.L. Ebi, et al. Human Health. In Fourth Natl. Climate Assessment, Volume II. U.S. Global Change Research Program, Washington, DC, NOAA

2019 Was the 2nd-Hottest Year Globally on Record, &  Ocean Temperatures Are Hotter Than Ever, Time Mag., Jan. 16, 2020

J. Samelow, Congratulations, You Just Survived the 5 Hottest Years on Record, Wash. Post, Feb 2019

Pullano. U.S. Medical Groups Warn Candidates: Climate Change Is a ‘Health Emergency’. Inside Climate News. June 2019; and US Call to Action on Climate, Health and Equity (pdf)

Gonzalez, Huge Costs in Climate Inaction, Business Insurance, Jan 2019

Hubau, et al. Asynchronous carbon sink saturation in African and Amazonian tropical forests. Nature, March 2020; Tollefson, World’s oceans are losing power to stall climate change, Nature, Sept 2019; and, IPCC, Special Report on the Ocean and Cryosphere in a Changing Climate, Sept 2019

Turetsky et al. Nature Geoscience | VOL 13 | February 2020, and Science Daily, Arctic permafrost thaw plays greater role in climate change than previously estimated, Feb 3, 2020

Hu et al. Deep-reaching acceleration of global ocean circulation over the past two decades Science Advances. 05 Feb 2020; C. Mooney. Oceans speeding up: another mega-scale consequence of climate change. Wash Post, Feb. 5 2020.

A. Woodward, Melting ice is slowing down the Atlantic ocean’s circulation system. Business Insider, Sept 26, 2019.

Berdugo, et al. Global ecosystem thresholds driven by aridity. Science, 2020; 367 (6479): 787; Major study shows climate change can cause abrupt changes to dryland ecosystems. ScienceDaily, Feb 2020.

Palmer, et al. The scientific challenge of understanding and estimating climate change. PNAS. Dec 2019. Climate models have been generally ineffective at demonstrating the growing understanding by scientists of climate system sensitivities. This limits policymakers’ abilities to address the increasing magnitude of the global warming challenge.


Few pathways to an acceptable climate future without immediate action, March 11, 2019. Note the IPCC assesses only a handful of future climate pathways.

Lamontagne et al. Robust abatement pathways to tolerable climate futures require immediate global actionNature Climate Change, 2019

J. Rockström, The Global Climate Emergency, Swedish Radio, Dec 2019 “We don’t want to push the ‘on’ buttons of runaway global warming. The next decade is our window…with consequences for all future generations.”

UN Intergovernmental Panel on Climate Change, Global Warming of 1.5 ºC, Oct 2018

Herrando-Pérez et al. Statistical Language Backs Conservatism in Climate-Change Assessments. BioScience, March 2019

Study shows IPCC is underselling climate change; IPCC assessments are inherently conservative as they require scientific then political consensus from governments across the globe.

United Nations Environment Program, Emissions Gap Report 2019, Nov 2019

UN Framework Convention on Climate Change (UNFCCC), The Paris Agreement, Dec 2015

United Nations Environment Program, Emissions Gap Report 2019, Nov. 2019

UN Framework Convention on Climate Change (UNFCCC), The Paris Agreement, Dec 2015.


Goss et al. Climate change is increasing the risk of extreme autumn wildfire conditions across California. Environmental Research Letters. March 2020. Extreme fire weather days in CA have doubled since 1980s but could be curbed with emissions reduction efforts.

Bedsworth et al. California’s Fourth Climate Change Assessment  Jan 2019.

Roston and Bloomberg. The Massive Cost of Not Adapting to Climate Change, Fortune, Sept  20, 2019

Gonzalez, Huge Costs in Climate Inaction, Business Insurance, Jan 2019

Drawdown 2020 Review, March 2020

Governor’s office. Climate Pollution continues to drop below 2020 target while state’s economy grows. Aug 2019

Rogers, California has 5 times more clean energy jobs than fossil fuel jobs. SJ Mercury News. Aug 20 2019.

California Air Resources Board, Natural and Working Lands, 2020.

For more on bold accelerated climate targets, see: CopenhagenNorwayUruguayFinland, and Rhode Island.

California voters call climate change their top priority, LA Times, Dec 6 2019; PPIC, Californian’s Views on Climate Change. July 2018.


  • Climate-Safe California is defined as CA becoming a net carbon sink with sequestration greater than emissions, achieving initial stages of drawdown by 2030.
  • Net-negative emissions are defined as sequestration of greenhouse gases (GHGs) greater than emissions, starting drawdown.
  • This suite of policies will be updated with the latest science, and input from experts and partners.
  • Existing state policies call for achieving 80% below 1990 levels of GHGs by 2050 (Governor Schwarzenegger Executive Order S-3-05 2005) and “maintaining net-negative emissions” after achieving carbon neutrality by “no later than 2045” (Governor Jerry Brown Executive Orders B-55-18 2018). 80% below 1990 levels of 431 MMT CO2e equals 86 MMT of CO2e annual emissions by 2030.
  • California could sequester an additional 100+ MMT CO2e annually from the atmosphere by 2030 with vastly increased investments in nature-based sequestration on natural and working lands if the investments begin to scale up by ~2022. These investments would also provide other ecosystem services or benefits including increased soil water holding capacity, biodiversity, food security, and resilience to extreme events.
  • California Natural and Working Lands Climate Change Implementation Plan Draft Jan 2019. Projected outcomes per this draft plan’s level of investment for cumulative emissions reductions for the state are up to 56.8 MMT CO2e by 2030. Sequestration estimates range from 31 to 147 MMT CO2e by 2030 per these studies below.
    • Cameron, D. et al. (2017) Ecosystem management and land conservation can substantially contribute to California’s climate mitigation goals. Proceedings of the National Academy of Sciences;
    • Marvin, D. et al. (2018). Toward a Carbon Neutral California. Next10.
  • Combined with reaching measured emissions reductions of 80% below 1990 levels or 86 MMT of annual CO2e emissions by 2030, the state could reach -14 MMT CO2e annually, starting drawdown. Nascent negative emissions technologies could likely scale up by the 2030’s to further increase atmospheric drawdown of GHGs.
  • World Resources Institute. Leaving no worker behind in shifting to a low-carbon future. March 2019.
  • California Senate Bill 379 (2015) requires that “all cities and counties to include climate adaptation and resiliency strategies in the Safety Elements of their General Plans upon the next revision beginning January 1, 2017” but provides no funds to pay for this.
  • New bills being considered in the California state legislature address community resilience include SB 1240 (Senator Nancy Skinner) Utility Reform Planning and SB 1314  (Senator Bill Dodd) the Community Energy Resilience Act, prioritizing initial efforts in lower income communities.
  • There were approximately 240 million passengers at California’s top 8 airports in 2018. If each paid a $10 Climate-Safe California fee, the state could secure ~$2.4 billion annually.