Diplomats from more than 190 nations recently held talks at a United Nations global warming conference in Lima, Peru, to pave the way for an international treaty they hope to forge next year. At present, the numbers are stark. Carbon dioxide emissions: up 60 percent. Global temperature: up six-tenths of a degree. Population: up 1.7 billion people. Sea level: up 3 inches. U.S. extreme weather: up 30 percent. Ice sheets in Greenland and Antarctica: down 4.9 trillion tonnes of ice. To see how much the globe has changed since the first such international conference – the Earth Summit in Rio de Janeiro in 1992 â€“ Here is the crux of databases from around the world.
Since 1992, there have been more than 6,600 major climate, weather and water disasters worldwide, causing more than $1.6 trillion in damage and killing more than 600,000 people.
Extreme weather has noticeably increased over the years. From 1983 to 1992, the world averaged 147 climate, water and weather disasters each year. Over the past 10 years, that number has jumped to an average 306 a year.
In the United States, an index of climate extremes â€” hot and cold, wet and dry â€” kept by the National Oceanic and Atmospheric Administration has jumped 30 percent from 1992 to 2013, not counting hurricanes, based on 10-year averages.
NOAA also keeps track of US weather disasters that cost more than $1 billion, when adjusted for inflation. Since 1992, there have been 136 such billion-dollar events.
Worldwide, the 10-year average for weather-related losses adjusted for inflation was $30 billion a year from 1983-92. From 2004 to 2013, the cost was more than three times that on average, or $131 billion a year.
It’s almost a sure thing that 2014 will go down as the hottest year in 135 years of record keeping. If so, this will be the sixth time since 1992 that the world set or tied a new annual record for the warmest year.
The globe has broken six monthly heat records in 2014 and 47 since 1992. The last monthly cold record set was in 1916.
So, the average annual temperature for 2014 is on track to be about 58.2 degrees (14.6 degrees Celsius), compared with 57.4 degrees (14.1 degrees Celsius) in 1992. The past 10 years have averaged a shade below 58.1 degrees (nearly 14.5 degrees Celsius) â€” six-tenths of a degree warmer than the average between 1983 and 1992.
The world’s oceans have risen by about 3 inches since 1992 and gotten a tad more acidic â€” by about half a percent â€” thanks to chemical reactions caused by the absorption of carbon dioxide. Every year sea ice cover shrinks to a yearly minimum size in the Arctic in September â€” a measurement that is considered a key climate change indicator. From 1983 to 1992, the lowest it got on average was 2.62 million square miles. Now the 10-year average is down to 1.83 million square miles.
That loss â€” an average 790,000 square miles since 1992 â€” overshadows the slight gain in sea ice in Antarctica, which has seen an average gain of 110,000 square miles of sea ice over the past 22 years.
The world’s population in 1992 was 5.46 billion. Today, it’s nearly a third higher, at 7.18 billion. That means more carbon pollution and more people who could be vulnerable to global warming.
The effects of climate change can be seen in harsher fire seasons. Wildfires in the western United States burned an average of 2.7 million acres each year between 1983 and 1992; now that’s up to 7.3 million acres from 1994 to 2013.
And some of the biggest climate change effects on land are near the poles, where people don’t often see them. From 1992 to 2011, Greenland’s ice sheet lost 3.35 trillion tonnes of ice. Antarctica lost 1.56 trillion tonnes of ice over the same period.
Scientists simply point to greenhouse gas emissions, mostly carbon dioxide that forms a heat-trapping blanket in our air.
There’s no need to average the yearly amount of carbon dioxide pollution: It has increased steadily, by 60 percent, from 1992 to 2013. In 1992, the world spewed 24.9 billion tonnes of carbon dioxide; now it is 39.8 billion tonnes.
China has tripled its emissions from 3 billion tonnes to 11 billion tonnes a year. The emissions from the US have gone up more slowly, about 6 percent, from 5.4 billion tonnes to 5.8 billion tonnes. India also has tripled its emissions, from 860 million tonnes to 2.6 billion tonnes. Only European countries have seen their emissions go down, from 4.5 billion tonnes to 3.8 billion tonnes.