Global temperatures increase rapidly

Over the past century, temperatures have risen above the previous 1200 years ( Photo: AP ).

New evidence of a particularly warm world has just been published in Science magazine. New research shows that never during the past 1200 years, the Northern Hemisphere has become as warm as it is today.

Researchers believe that the new analysis is clearer than the previous study. Previous results were similar, but criticized by critics as technical flaws.

The average temperature has increased rapidly in the past few decades. Last year was the warmest year in history.

Researchers say warmth like in the 20th century has never happened since thousands of years, at least in the Northern Hemisphere. Research results are given in the 2001 international assessment report on climate change. Critics deny the conclusion and say that extreme periods in some parts of the earth have occurred since the Middle Ages.

The new study aims to discuss what critics aim at by looking at regional temperature patterns over the past millennium. The results showed that although there were sometimes warm periods, only by the end of the 20th century did the temperature in areas across the Northern Hemisphere heat up. Data analysis is also made simpler than previous studies to avoid accusations that computational problems make the climate picture misleading.

Scientists conducting research from the UK, collected evidence from specimens taken from ice cores and fossil samples from various places, from North America, the Nordic peninsula to Siberia.

Scientists also use records from the Middle Ages and tell witnesses about unusual weather phenomena over the centuries.