The Intergovernmental Panel on Climate Change (IPCC) is a scientific body under the auspices of the United Nations (UN). It reviews and assesses the most recent scientific, technical and socio-economic information produced worldwide relevant to the understanding of climate change. It is the leading international body for the assessment of climate change. It was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988 to provide the world with a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts.
The European Environment Agency (EEA) is an agency of the European Union. Its task is to provide sound, independent information on the environment. They have a lot of interesting stuff to read. Start for instance at The cost of ignoring the warning signs - EEA publishes ‘Late Lessons from Early Warnings, volume II’.
In 2015 InsideClimate news presented Exxon: the road not taken, a multi-part history of Exxon's engagement with the emerging science of climate change. It spans four decades, and is based on primary sources including internal company files dating back to the late 1970s, interviews with former company employees, and other evidence. Exxon conducted cutting-edge climate research decades ago and then, without revealing all that it had learned, worked at the forefront of climate denial, manufacturing doubt about the scientific consensus that its own scientists had confirmed.