REPORTS AND PAPERS

THE IPCC

In 1988 NASA scientist James Hansen warned lawmakers in the US Senate of the looming dangers presented by global warming which humans were accelerating. The same year, the United Nations (UN) and the World Meteorological Organization (WMO) formed the Intergovernmental Panel on Climate Change (IPCC) to report to world leaders on the science of climate change.

Two years later, in 1990, the First IPCC Assessment Report (FAR) was published, underlining the importance of climate change as a challenge with global consequences and requiring international cooperation. It was followed by the 2nd (1995), 3rd (2001), 4th (2007), 5th (2013-2014), and 6th (2021-2023) assessment reports. 

U.S. SIGNS THE PARIS AGREEMENT 

On December 12, 2015 in Paris at the United Nations Climate Change Conference, COP 21, the now-infamous Paris Agreement was written with an objective to combat climate change and to accelerate and intensify the actions and investments needed for a sustainable low carbon future. It entered into force on November 4, 2016 by which time it had been ratified by 55 countries(accounting for 55% of global emissions). Within the following two years 197 countries signed on, including the U.S.

U.S. WITHDRAWS FROM THE PARIS AGREEMENT 

In the summer of 2017 President Trump announced that the U.S. would withdraw from the Paris Agreement. On November 4, 2019 the U.S. submitted formal notification of its withdrawal to the UN. On November 4, 2020, the withdrawal took effect. Polls show the majority of voters opposed the withdrawal. In response, 24 governors formed the U.S. Climate Alliance of members committed to achieving the goals of the Paris Agreement.

U.S. REJOINS THE PARIS AGREEMENT

President Biden signed an executive order on January 20, 2021 to rejoin the Paris Agreement, formally rejoining on February 19, 2021,

U.S. WITHDRAWS FROM THE PARIS AGREEMENT AGAIN

On January 20, 2025, Trump signed an executive order to withdraw the United States from the Paris Agreement again.  U.S. from the Paris Agreement again. 

OTHER REPORTS

• In 2017, a variety of climate groups worked together to release 2020: The Climate Turning Point, which talks about how GHG emissions must begin declining rapidly by 2020 if the world is to avoid crossing the temperature threshold agreed to in the Paris Climate Accords.
• In 2018, came the Fourth National Climate Assessment Report, a U.S. report written for the president every four years. This report focused heavily on climate change’s impact on the American economy.
• In 2019, the words “Green New Deal” entered the lexicon, prompting One Earth to study the potential impacts of such legislation on grid stability in 143 countries.
• In 2020 we began to see significant reports on the economy as it pertained to climate change, on sea level rise and flooding, food security and nutrition, water management, the plastic pollution of our oceans, climate induced migration, and disease. There was a critical one on the dangers of the growing demand for cooling, as our world warms, and finally, one with some optimism from The Goldman school of Public Policy in Berkeley, California suggesting that it is still possible, with some robust policy reforms, for the U.S. to achieve 90% clean, carbon-free electricity nationwide by 2035.
• By early June, 2021 we had already read dozens of additional reports on subjects from air quality to conserving and restoring America’s lands and waters, from melting ice to gas emission inventories, from health consequences to economic consequences, not to mention the deforestation of the Amazon. Perhaps IEA’s report Net Zero by 2050 released on May 1, is the one you should read first. It is both demanding and optimistic.
• The IPCC’s highly-anticipated Sixth Assessment Report was released in four volumes from 2021-2023: Climate Change 2021: The Physical Science Basis was released in August 2021; Climate Change 2022: Impacts, Adaptation, and Vulnerability in February 2022; Climate Change 2022: Mitigation of Climate Change in April 2022; and the Synthesis Report, Climate Change 2023: Synthesis Report was released in March 2023.
  This dire landmark report details how humans have altered the environment at an unprecedented pace, and cautions that the world risks increasingly catastrophic impacts in the absence of rapid greenhouse gas reductions. According to UN Secretary General Antonio Guteress, the report “is a clarion call to massively fast-track climate efforts by every country and every sector and on every timeframe.”

ACCESSIBILITY OF REPORTS

• The IPCC is dedicated to making its reports available, with video summaries of each report available on YouTube featuring interviews from chairs of each working group, as well as summaries for policymakers on the website.
  While the first Trump White House managed to delay its scheduled publication by a year, and attempted to downplay its significance (Trump: “I don’t believe in it”), the 5th National Climate Assessment was released in 2023, under a Biden appointed director Alison Crimmins. 
• During the second Trump presidency, as of July 2025 the National Climate Assessment website has gone dark. A crucial source of information on how climate change will impact the U.S., the NCA is mandated by Congress to be released every four years, with the next one due for 2027.
• Work had already begun on the 6th National Climate Assessment when the federal staff were let go in April, making the future of the report uncertain.
   While the official NCA website remains inaccessible, a July 2025 NPR article lists some of the places where you can still find the data. 
• As a supplement to the NCA, the NOAA also publishes the State Climate Summaries which, as of August 2025, remain accessible. Its latest version from 2022 provides historical and predicted climate conditions for each state. 
• Looking forward, the IPCC is currently in its Seventh Assessment cycle. The Seventh Assessment Report will be released in four volumes culminating in a Synthesis Report in 2029. It will also include a Special Report on Climate Change and Cities and a Methodology Report on Carbon Dioxide Removal Technologies, Carbon Capture Utilization and Storage, both set for release in 2027. 
• There are a number of websites releasing reports on a regular basis that are worth checking out for the newest on climate change. 
• The Lancet releases an annual countdown report on the intersections of climate change and public health.
• The World Meteorological Organization (WMO) releases an annual “State of the Global Climate” report, in addition to annual state of the climate reports for different regions (2024 can be found here). 
• The NOAA produces monthly and annual climate reports, impressive for their immense scope, detail, and readability. These reports include national overviews, analyses of temperature and precipitation, overviews of billion-dollar climate disasters, and regional highlights.