My question is - are we to assume that humans have had NO effect on global warming?

CLIMATE SCIENCE

Global climate is always changing in accordance with natural causes and recent changes are not unusual.

Science is rapidly evolving away from the view that humanity's emissions of carbon dioxide and other 'greenhouse gases' are a cause of dangerous climate change.

Climate models used by the IPCC* fail to reproduce known past climates without manipulation and therefore lack the scientific integrity needed for use in climate prediction and related policy decision-making.

The UN IPCC Summary for Policymakers and the assertions of IPCC executives too often seriously misrepresent the conclusions of their own scientific reports.

Claims that ‘consensus’ exists among climate experts regarding the causes of the modest warming of the past century are contradicted by thousands of independent scientists.

Carbon dioxide is not a pollutant - it is a necessary reactant in plant photosynthesis and so is essential for life on Earth.

Research that identifies the Sun as a major driver of global climate change must be taken more seriously.

Global cooling has presented serious problems for human society and the environment throughout history while global warming has generally been highly beneficial.

It is not possible to reliably predict how climate will change in the future, beyond the certainty that multi-decadal warming and cooling trends, and abrupt changes, will all continue, underscoring a need for effective adaptation.

Since science and observation have failed to substantiate the human-caused climate change hypothesis, it is premature to damage national economies with `carbon' taxes, emissions trading or other schemes to control 'greenhouse gas' emissions.