The following is a list of some of the common myths associated with climate change. The very brief replies give only bare bones summaries of the relevant facts.
Global warming stopped in 1998
Warming of the air did slow somewhat after 1998, a strong El Nino year of unusually high temperature. However, the 2000s were warmer than the 1990s. Most of the excess heat due to CO2 is stored in the oceans. Year-to-year variations in air temperature are due to heat sloshing back and forth between the air and the oceans. Overall, the trend in air and ocean temperatures is upward. Several months in 2014 set records for average global temperature. For example, at 15.7 degrees C, September 2014 was the hottest in 135 years of record keeping. That trend continues. January 2016 was the ninth month in succession having a record high temperature.
The oceans are cooling
There are a variety of ways to measure the heat content of the oceans. While some years may show a slight decrease in ocean temperatures and while the data reported by different measuring teams may not always agree, the consensus is that since 1970 there has been an undeniable significant upward trend. In 2014, ocean surface temperatures have been the highest on record. For example, in July 2014 the surfaces were 0.55 degrees C higher than the average since 1890, just beating the previous record set in the strong El Nino year 1998.
Growth of Antarctic ice disproves global warming
While Arctic ice has decreased by at least 15% in the last 30 years, Antarctic ice has increased by 5%. Possible explanations are that changing wind patterns have lessened the flow of warm air southward and that Antarctic icebergs, recently growing in number, have created a cool surface layer of fresh water as they melt.
The hockey stick graph has been proven wrong
There was a debate about the statistics in the early 2000s, but subsequent analysis shows that the original graph was not far off the mark. Within the last 1000 years, the world has never been warmer than in the second half of the last century.
Polar bear numbers are increasing
There may be as many as 25,000 polar bears distributed among 19 groups around the arctic. Total populations are difficult to measure. In groups that are under intense study numbers have indeed increased. But their future is not secure. Loss of habitat due to warming has led to reduced adult weight and reduced cub survival.
It has been far warmer in the past, what’s the big deal
There have been periods of glaciation followed by warming at intervals of about 100,000 years, largely due to slow changes in the earth’s orbit. These changes in climate were always very disruptive, involving mass extinctions and large changes in ocean levels. Typically, it took thousands of years for the temperature to rise by a few degrees. If CO2 emissions continue at current levels, we may see a rise of 4 degrees C by 2100.
Global warming is down to the sun, not us
There is no correlation between solar output and the rapid warming of the last several decades. Recent measurements of solar activity show the usual rise and fall over the 11-year sunspot cycle, but no upward trend that could account for the observations.
Carbon dioxide is not the most important greenhouse gas
Water in the form of vapor and clouds is important, but the amount of water in the atmosphere depends on temperature. Any excess rains out within days. Excess CO2, however, accumulates and causes long-term warming. If CO2 emissions ceased tomorrow, it would take hundreds of years to return to pre-industrial levels in the atmosphere.
Human Emissions of CO2 are too small to matter
Data from ice cores show that for a half million years the concentration of CO2 in the atmosphere varied from 180 to 300 parts per million. In recent centuries the level has risen sharply, to 400 ppm in 2013. In the past, there was a balance between natural emissions and natural sinks. Massive increases in the use of fossil fuels and in deforestation have upset the balance.
Higher CO2 levels will boost plant growth and food production
Predicting the effect of increased CO2 on food production is virtually impossible. Regional climate changes and their limiting effects, such as water shortage, have to be considered. These limiting effects will very likely offset any CO2 fertilization.
Many leading scientists question climate change
Scientific predictions will always be debated. That is how consensus is reached. In 2009, in reply to the question “ Do you think that human activity is a contributing factor in changing mean global temperature?” 82% of over 3000 earth scientists asked and 75 of the 77 active climatologists answered yes. These numbers would likely be higher today as a result of the growing body of evidence.
We can’t do anything about climate change
Climate change will continue but we can take steps to slow the warming and to mitigate the effects. The world can increase investment in alternative technologies. Carbon storage and capture can save us some time. As individuals we have a responsibility to reduce our own use of fossil fuels and to hold our governments at all levels accountable for their actions.