What is a science-based climate target?

Science-based targets are measurable and actionable targets that allow cities, states and regions to align their actions with societal sustainability goals and the biophysical limits that define the safety and stability of earth systems.

Targets adopted by cities, states and regions to reduce greenhouse gas (GHG) emissions are considered “science-based” if they are in line with the goals of the Paris Agreement to pursue efforts to limit warming to 1.5 °C. As well as considering the latest science, a science-based target should account for equity and be comprehensive in the GHGs and emission sources included.

Why should cities and states and regions set science-based targets?

Giving cities, states and regions the confidence that their targets are ambitious enough: The science is telling us that globally we need to halve emissions by 2030 and reach net zero by 2050 but how does this target translate down to individual cities? What does this mean for a small town in Nepal versus a large city in the United States? A science-based target tells cities, states and regions what their individual contribution should be to this global goal. It means cities, states and regions can be confident that their planned emissions reductions are in line with what is needed globally to limit warming to 1.5°C, and confident that they are taking the appropriate action to combat climate change.

Ensuring that cities, states and regions start making deep emissions cuts now: The IPCC Special Report on Global Warming of 1.5°C shows that to limit global warming to 1.5°C, we have an estimated remaining carbon budget of somewhere between 420 and 770 GtCO2 (although there are large uncertainties in these estimates). Currently, we are depleting that global budget by 42 GtCO2 per year. At that rate, we will use up our remaining carbon budget somewhere between 2030 and 2040, long before our target to be net zero by 2050. To ensure that we do not use up our remaining carbon budget in the next 10 to 20 years, we need to start making deep emissions cuts now. Setting a science-based mid-term target is critical for ensuring that cities, states and regions do the same. The more progress that can be made now, the easier it will be for cities, states and regions to reach their long-term net zero targets.

Enabling cities, states and regions to track their progress: Having a science-based target is important for enabling cities, states and regions to track their progress towards net zero. This is because they are measurable, connecting percentage reduction targets to cities’, states and regions actual measured emissions, and because they include mid-term target. The mid-term target ensures that they start reducing their emissions early and that they stay on a pathway designed to reach net zero by 2050.

Meeting the Race to Zero requirements: Setting a science-based target it one of the requirements of the Race to Zero campaign; the UNFCCC’s global movement of actors subnational governments committing to reach net zero by 2050.

What support is available for setting science-based climate targets? 

For cities

CDP is supporting cities to set, check and disclose science-based climate targets. To access this support, report your current or updated target to CDP-ICLEI Track in 2022.

For additional support:

  • Read the Science Based Target Network’s Guide for Cities
  • Watch our recorded and upcoming webinars on our Events page

Read our guidance on cities disclosure. If you have questions, contact us via My Support the Help Center.
Cities that are members of ICLEI and C40 Cities will receive target setting support from these organisations.

For states and regions

For support on how to set, check and update science-based climate targets, read the Science Based Target Network’s Guide for Cities and watch our recorded and upcoming webinars on our Events page. Support is also available for States and Regions through the Climate Group, find out more here:

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