Extract from Professor Richard Lindzen Open Letter to President Trump

We note that:

• The UN’s Intergovernmental Panel on Climate Change (IPCC) no longer claims a greater likelihood of significant as opposed to negligible future warming,
• It has long been acknowledged by the IPCC that climate change prior to the 1960’s could not have been due to anthropogenic greenhouse gases.   Yet, pre-1960 instrumentally observed temperatures show many warming episodes, similar to the one since 1960, for example, from 1915 to 1950, and from 1850 to 1890. None of these could have been caused by an increase in atmospheric CO2,
• Model projections of warming during recent decades have greatly exceeded what has been observed,
• The modelling community has openly acknowledged that the ability of existing models to simulate past climates is due to numerous arbitrary tuning adjustments,
• Observations show no statistically valid trends in flooding or drought, and no meaningful acceleration whatsoever of pre-existing long term sea level rise (about 6 inches per century) worldwide,
• Current carbon dioxide levels, around 400 parts per million are still very small compared to the averages over geological history, when thousands of parts per million prevailed, and when life flourished on land and in the oceans.