People are beginning to consider the serious economic and environmental consequences if we fail to reduce global carbon emissions quickly.
- International travel observation:
Global warming is likely to increase the number of “climate refugees” — people who are forced to leave their homes because of drought, flooding, or other climate-related disasters. Migration of people may lead to conflict, and might even lead to war.
Societies may find ways to prepare for and cope with some climate impacts. However, coping is likely to be more expensive than steps to reduce carbon emissions.
For example, farmers might need to irrigate areas that used to receive rain, they will need to keep animals cool, and they will have to stop more pests and diseases. Governments spend money making sure that houses are more energy efficient, and build early warning systems for heat waves and disasters and build more emergency services. Governments may also have to build seawalls, stop sewer overflows, and make bridges and subways stronger.
However, rebuilding after disasters is likely to be even more costly than preparing for the disasters. And these costs do not include deaths and consequences which cannot be reversed.
- International travel discovery:
We do not have a lot of understanding of the climate during glacial-interglacial cycles, but new studies are providing us with more information about the topic. This growing information is helpful, for it gives us a long history to compare the current climate with and to see if it is unique.
It has been claimed by some scientists, for example, that the continuing rise in the amount of CO2 in the air actually made the 1990s the warmest period of the entire past million years (Mann et al., 1998, 1999). “Unprecedented” is the word that supporters of this idea frequently use to describe the current temperature of the globe. However, this is simply not true, and, in fact, when the average temperature of the 1990s is compared with the warmest temperatures of the last four interglacials (which we have excellent temperature records for), the 1990s are found to have been much cooler than all of these other periods.
For example, a temperature history made from the Vostok ice core in East Antarctica that covers the past 420,000 years determined that “the temperature … [238,000 years ago] was slightly warmer than the Holocene [the current interglacial].” It also noted that the inter-glacials before and after the one at 238,000 years ago were even warmer. In fact, it can be seen that all of the last four inter-glacials were warmer than the current one by an average temperature in excess of 2°C.
Similar discoveries have been found from the Dome Fuji ice core, which was taken from a site in an entirely different part of East Antarctica that is separated from the Vostok ice-core site by 1500 km (Watanabe et al., 2003). Although this study only covered the last three glacial-interglacial periods, it also reveals that the last three interglacial “were much warmer than the most recent 1,000 years (from 4.5°C – 6°C).”
“A study of an ice core from a mountain range in northwest Greece has revealed that the last ice age started about 10,800 years after the beginning of the last interglacial period.”
