The Azimuth Project
NRC climate stabilization targets

Contents

Introduction

This page is about the NRC climate stabilization targets that address Climate change.

Sources

Here is some information from the following report:

Here are their estimates of global temperature rise as a function of atmospheric carbon dioxide concentrations:

And here are some of their predictions. (It would be nice to flesh these out a bit, and also sketch any recommendations they have, while still keeping this summary easy to read. The idea is to make lots of such summaries easily available in one place, to provide an overall view.)

• For 3 °C of global warming, 9 out of 10 northern hemisphere summers will be “exceptionally warm”: warmer in most land areas than all but about 1 of the summers from 1980 to 2000.

• Increases of precipitation at high latitudes and drying of the already semi-arid regions are projected with increasing global warming, with seasonal changes in several regions expected to be about 5-10% per degree of warming. However, patterns of precipitation show much larger variability across models than patterns of temperature.

• Large increases in the area burned by wildfire are expected in parts of Australia, western Canada, Eurasia and the United States.

• Extreme precipitation events — that is, days with the top 15% of rainfall — are expected to increase by 3-10% per degree of warming.

• In many regions the amount of flow in streams and rivers is expected to change by 5-15% per degree of warming, with decreases in some areas and increases in others.

• The total number of tropical cyclones should decrease slightly or remain unchanged. Their wind speed is expected to increase by 1-4% per degree of warming.

• The annual average sea ice area in the Arctic is expected to decrease by 15% per degree of warming, with more decrease in the summertime.

• Global sea level has risen by about 0.2 meters since 1870. The sea level rise by 2100 is expected to be at least 0.6 meters due to thermal expansion and loss of ice from glaciers and small ice caps. This could be enough to permanently displace as many as 3 million people — and raise the risk of floods for many millions more. Ice loss is also occurring in parts of Greenland and Antarctica, but the effect on sea level in the next century remains uncertain.

• Up to 2 degrees of global warming, studies suggest that crop yield gains and adaptation, especially at high latitudes, could balance losses in tropical and other regions. Beyond 2 degrees, studies suggest a rise in food prices.

• Increased carbon dioxide also makes the ocean more acidic and lowers the ability of many organisms to make shells and skeleta. Seashells, coral, and the like are made of aragonite, one of the two crystal forms of calcium carbonate. North polar surface waters will become under-saturated for aragonite if the level of carbon dioxide in the atmosphere rises to 400-450 parts per million. Then aragonite will tend to dissolve, rather than form from seawater. For south polar surface waters, this effect will occur at 500-660 ppm. Tropical surface waters and deep ocean waters are expected to remain supersaturated for aragonite throughout the 20th century, but coral reefs may be negatively impacted.

• Species are moving toward the poles to keep cool: the average shift over many types of terrestrial species has been 6 kilometers per decade. The rate of extinction of species will be enhanced by climate change.

category: climate, reports