Climate Change Weekly #67
A pair of newly published papers confirms prior studies indicating temperatures during the Medieval Warm Period and Roman Warm Period were at least as warm as temperatures in the current warm period.
Scandinavian scientists examined dozens of temperature proxies covering the past two millennia and found “a well-defined Medieval Warm Period.” Writing about their findings in Climate of the Past, a journal of the European Geosciences Union, the scientists report “a rather geographically homogeneous Little Ice Age” following the Medieval Warm Period. Current temperatures are rebounding from the depths of the Little Ice Age.
In a separate study, a team of scientists examined proxy records for 2,000 years of summer temperatures in northern Scandinavia. Summarizing their findings in the peer-reviewed Journal of Global and Planetary Change, the scientists report temperatures were higher during the Medieval Warm Period and Roman Warm Period than today.
“The first century AD was the warmest 100-year period (+0.60 °C on average relative to the 1951–1980 mean) of the Common Era,” the scientists report.
“Warmth during Roman and Medieval times [was] larger in extent and longer in duration than 20th century conditions,” conclude the scientists.
SOURCES: Watts Up With That?; Climate of the Past; and Journal of Global and Planetary Change
IN THIS ISSUE
Harris shows disconnect between CO2, temperatures … Curry: Natural variation ‘dominates’ CO2 … Goklany explains why warming is not a major threat … Study finds no long-term increase in Antarctic temperatures … Low pH will impact coral calcification only marginally
HARRIS SHOWS DISCONNECT BETWEEN CO2, TEMPERATURES
The lack of significant warming during the past 15 years shows a strong disconnect between carbon dioxide emissions and global temperatures, International Climate Science Coalition Executive Director Tom Harris explains on Sun News Network. The lack of warming, even as carbon dioxide emissions rise, illustrates how natural factors drive global temperature variations more than carbon dioxide emissions do, says Harris.
SOURCE: Sun News Network
CURRY: NATURAL VARIATION ‘DOMINATES’ CO2
The recent pause in global warming demonstrates natural variability dominates the greenhouse warming signal, ‘lukewarmist’ climate scientist Judith Curry reports on her Climate Etc. blog. “The data confirms the existence of a ‘pause’ in the warming. … The flawed assumption behind the orthodoxy was that natural variability is merely ‘noise’ superimposed on the long term trend. The natural variability has been shown over the past two decades to have a magnitude that dominates the greenhouse warming signal,” writes Curry.
SOURCE: Judith Curry
GOKLANY EXPLAINS WHY WARMING IS NOT A MAJOR THREAT
Far from being the “greatest threat to humanity,” climate change is a relatively minor concern compared to many other challenges facing humanity, scientist and policy analyst Indur Goklany explains in a new paper. Despite overstating the negative impacts of global warming, “the World Health Organization’s latest (2009) study on Global Health Risks provides estimates that indicate that global warming is presently outranked by at least 22 other health risk factors,” Goklany reports.
SOURCE: Watts Up With That?
STUDY FINDS NO LONG-TERM INCREASE IN ANTARCTIC TEMPERATURES
Scientists examining proxy data for Antarctic Ross Sea temperatures report no significant temperature trends between 1882 and 2006. Explaining their findings in the peer-reviewed Journal of Climate, the scientists further report a decrease in winter temperatures since 1979.
SOURCE: NIPCC Report
LOW pH WILL IMPACT CORAL CALCIFICATION ONLY MARGINALLY
Cold-water coral species show a surprising ability to adapt to lower pH, resulting in only marginal declines in calcification under low-pH conditions, a team of scientists reports in Geochimica et Cosmochimica Acta. “Cold-water corals are likely to be much more resilient to decreasing seawater pH from ocean acidification than previously realized,” the scientists conclude.
SOURCE: NIPCC Report and Geochimica et Cosmochimica Acta
