Read de texts below and answer the questions 1 and 2.

A)   

The Earth’s climate is a complex system, and yet the basic science of climate change is clear: the average temperature of the Earth’s surface has increased about 0.8 degrees Celsius since the Industrial Revolution. Deniers of climate change science have taken advantage of its complexity to discredit the consensus conclusion that the climate is changing most likely as a consequence of human activities, with potentially very negative impacts on society. Examples of findings that are often questioned include the average surface temperature increase inferred from global measurements, and the conclusion that the recent waves of extreme weather events are most likely connected with such an increase.

Available at <http://www.pas.va/content/dam/accademia/pdf/acta22/acta22-molina.pdf>.Acessed on November 21,2019.


B)   Climate is always changing. We have had ice ages and warmer periods when alligators were found in Spitzbergen. Ice ages have occurred in a hundred thousand year cycle for the last 700 thousand years, and there have been previous periods that appear to have been warmer than the present despite CO2 levels being lower than they are now. More recently, we have had the medieval warm period and the little ice age. 

Available at <https://quadrant.org.au/opinion/doomed-planet/2009/07/resisting-climate-hysteria/>.Acessed on November 21,2019.



a) What does the author of  text A and text B  declare?


b) Which arguments the authors of text A and text B respectively defend?