The Earth League

The 10 Science Must-Knows on Climate Change


(c) The Earth League and FutureEarth

Prepared by the Earth League and Future Earth for the
UNFCCC 23rd Conference of the Parties, 2017

The Paris Agreement aims to hold “the increase in the global average temperature to well below 2 °C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5 °C above pre-industrial levels”. In 2016, global average surface temperature reached about 1.1 °C above pre-industrial levels, making it the warmest year on record1. Globally averaged concentrations for carbon dioxide (CO2) reached 403.3 parts per million in 2016, up from 400.0 ppm in 2015. This is a record annual increase (2). The science is clear that meeting the Paris Agreement will require rapidly ridding society of fossil fuels. In addition, the world will have to safeguard and enhance existing carbon sinks, and major efforts will be needed to build societal resilience in the face of unavoidable climate change.
The following statements summarise key scientific insights relating to the Paris Agreement and economic and policy options that would help us reach these goals. These statements show that the climate challenge must be positioned in the larger context of global sustainability. With the 23rd Conference of the Parties taking place in Bonn in November, these statements are intended to provide climate negotiators, policy makers, and business leaders with an evidence-based briefing to advance solutions for a manageable climate future.

Dear Secretary Espinosa,

The UNFCCC’s Paris Agreement on climate change set the world on a new course towards a science-based target for maintaining a manageable and just climate future. Meeting this target of keeping global temperature rise below 2 °C while aiming for stabilising at 1.5 °C will not be easy. But it must be done. Climate change caused by humans is no longer a future threat: it has arrived, it is dangerous and it will get worse.
​It is critical for all parties in the climate negotiations to stay on top of the latest science in order to understand new and emerging risks and options to mitigate risk. It is in this context that we share with you and the delegates of COP23 a brief summary of the latest science, prepared by Future Earth and the Earth League, which sets out The 10 Science ‘Must Knows’ on Climate Change. This draws from and builds on numerous international science assessments and reports, for example, from the IPCC, WMO, and UN Environment, as well as the most recent analyses coming out of the scientific literature.
Today, the Global Carbon Project, sponsored by Future Earth and the World Climate Research Programme, published the 2017 global carbon budget. Following three years of almost no growth, In 2017, CO2 emissions from fossil fuels and industry are projected to grow by 2.0% (+0.8 to +3.0%). This news is deeply concerning. The world has not reached peak emissions yet. There is no room for complacency.
The science is clear; achieving the Paris Agreement is not only necessary, it is possible. But it is also clear that for society to develop and prosper in a near-to 2 °C world there must be a transformation to global sustainable development. Decarbonising the world economy by 2050-2070 is not enough. We also need to safeguard the resilience of all ecosystems on Earth, and transition to healthy and equitable societies for all world citizens, as expressed by the UN Sustainable Development Goals..
In short, a safe climate future depends on a transition to global sustainability, but global sustainability is also the only path to a safe climate future. This places COP23 centrally on the global stage of world development. Thank you for your leadership on this critical issue for humanity. We hope these “10 Science Must Knows” will provide support to all delegates in the COP23 climate negotiations.

Kind regards,

Johan Rockström
Chair, Earth League

Amy Luers
Executive Director, Future Earth

Please download full statement here; figures and references included.
​The 10 Science Must Knows on Climate Change (1,6 MB)

Below you find the individual chapters of the document.

Where do we stand?
How can we avoid dangerous impacts?
Why should we care?