Final answer:
The statement that is false is not provided among the options, as all listed statements A, C, and D are true based on scientific consensus and evidence, and statement B was true at the time but might need to be updated with more recent data.
Step-by-step explanation:
The question is asking which of the provided statements about climate change is false. To provide an accurate answer, we can analyze each statement based on the provided reference material:
- A) The IPCC's AR4 states that warming of the climate system is unequivocal. This statement is true according to the scientific consensus on global climate change.
- B) Twelve of the last 13 years, 1995--2007, rank among the warmest years in instrumental records stretching back to 1850. This statement was true at the time of the report's publication, but newer data would be needed to confirm its current accuracy.
- C) By the end of the 21st century, large portions of Earth's surface may experience climates not found at present. According to climate models, this is true and is a likely result of ongoing climate change.
- D) The Arctic is now experiencing some of the most rapid and severe climate change on Earth. This is true, as the Arctic has shown the greatest increase in temperatures, particularly as compared to other regions of the world.
Since all statements A, C, and D are supported as true by the scientific evidence provided, the only potential for a false statement lies with B, but only because it is outdated. Therefore, since the question asks which statement is false and does not qualify the timing, the answer is E) All of the above are true, with the caveat that statement B would need updating with recent data.