Introduction to Science

Science: why is there a need to act?

The international climate regime is built upon a clear understanding of the threats posed by, and the causes of climate change. More than a century and a half of industrialization, along with the clear-felling of forests and certain farming methods, has led to increased quantities of greenhouse gases (GHGs) in the atmosphere. There are some basic well-established scientific links:

The average global temperature on Earth is directly linked to the concentration of GHGs in the Earth’s atmosphere.

The concentration of GHGs has been rising steadily since the time of the Industrial Revolution as a result of human activity, primarily the burning of fossil fuels and changes in land use, leading to increasing global temperatures.

Urgent action is needed to reduce greenhouse gas emissions, enhance sinks and to adapt to the impacts of climate change.

The knowledge and understanding of climate change, its causes and impacts, are constantly growing in breadth and depth, based on Earth observations and scientific research by a large number of organizations and thousands of scientists from around the world.

Intergovernmental Panel on Climate Change Reports

The Intergovernmental Panel on Climate Change (IPCC) has a well-established role as the leading international body for the assessment of worldwide climate change research. It issues regular assessment reports and compiles special reports and technical papers. The findings of the IPCC reflect global scientific consensus and are apolitical in character. The IPCC is currently engaged in its sixth assessment cycle.

Scientific research in recent years provided more clarity about human-generated (anthropogenic) climate change than ever before. The IPCC released its Fifth Assessment Report (AR5), between 2013 and 2014. Its key findings are:

  • Human influence on the climate system is clear;
  • The more we disrupt our climate, the more we risk severe, pervasive and irreversible impacts;
  • We have the means to limit climate change and build a more prosperous, sustainable future.

The IPCC is currently in its Sixth Assessment cycle, during which the following reports are/will be published:

  • Global Warming of 1.5°C: an IPCC special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty (2018);
  • Special report on Climate Change and Land (SRCCL): an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems (2019);
  • Special report on the Ocean and Cryosphere in a Changing Climate (SROCC) (2019);
  • 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2019);
  • The Sixth Assessment Report (2022).

World Meteorological Organization Statement on the state of the global climate

The World Meteorological Organization (WMO) issues a statement on the state of the global climate every year. It is an authoritative source of reference based on multiple international datasets maintained independently by global climate analysis centres and information submitted by WMO Members’ National Meteorological and Hydrological Services and Research Institutes. Because the social and economic impacts of climate change have become so important, WMO partnered with other United Nations organizations for the first time in 2016 to include information on these impacts. Since 2016, the WMO provides the annual statement on the state of the global climate at the COP.