nuclear-news

The News That Matters about the Nuclear Industry

The reasons for the global inaction on climate change

Curbing climate change: Why it’s so hard to act in time, The Conversation   Timothy H. Dixon
Professor, Geology and Geophysics, Natural and human-caused hazards, sea level rise and climate change, University of South Florida,  August 18, 2017
 This summer I worked on the Greenland ice sheet, part of a scientific experiment to study surface melting and its contribution to Greenland’s accelerating ice losses. By virtue of its size, elevation and currently frozen state, Greenland has the potential to cause large and rapid increases to sea level as it melts.

When I returned, a nonscientist friend asked me what the research showed about future sea level rise. He was disappointed that I couldn’t say anything definite, since it will take several years to analyze the data. This kind of time lag is common in science, but it can make communicating the issues difficult. That’s especially true for climate change, where decades of data collection may be required to see trends.

A recent draft report on climate change by federal scientists exploits data captured over many decades to assess recent changes, and warns of a dire future if we don’t change our ways. Yet few countries are aggressively reducing their emissions in a way scientists say are needed to avoid the dangers of climate change.

While this lack of progress dismays people, it’s actually understandable. Human beings have evolved to focus on immediate threats. We have a tough time dealing with risks that have time lags of decades or even centuries. As a geoscientist, I’m used to thinking on much longer time scales, but I recognize that most people are not. I see several kinds of time lags associated with climate change debates. It’s important to understand these time lags and how they interact if we hope to make progress.

Agreeing on the goal

Changing the basic energy underpinnings of our industrial economy will not be easy or cheap, and will require broad public support……

Designing cleaner technologies

It will also take time for technological developments to support our transition to a low-carbon energy future. Here, at least, there is reason for optimism. A few decades ago renewable energy sources such as wind and solar seemed unlikely to replace a significant fraction of carbon-based energy. Similarly, electric vehicles seemed unlikely to meet a significant share of our transportation needs. Today both are realistic alternatives……

Funding the transition

Once we finally decide to make a low-carbon transition and figure out how to do it, it will cost trillions of dollars. Capital markets can’t provide that sort of funding instantaneously……

The natural carbon cycle

Our ability to add carbon dioxide to the atmosphere greatly exceeds nature’s ability to remove it. There is a time lag between carbon emission and carbon removal. The process is complicated, with multiple pathways, some of which operate over centuries…….. most of the carbon dioxide that we put into the atmosphere today will continue to heat the world for hundreds to thousands of years.

Today the concentration of carbon dioxide in the atmosphere is just over 400 parts per million, rising by about 3 ppm yearly. Given the political, technological and economic time lags that we face, it’s likely that we will hit at least 450-500 ppm before we can seriously curtail our carbon emissions. The last time Earth’s atmosphere contained this much carbon dioxide was several million years ago, during the Pliocene era. Global temperatures were much higher than 2°C above today’s average, and global sea level was at least 6 meters (nearly 20 feet) higher.

We haven’t seen comparable temperature or sea level increases so far because of time lags in Earth’s climate response. It takes a while for our elevated carbon dioxide levels to trigger impacts on this scale. Given the various time lags that are in play, it is quite possible that we have already exceeded the 2°C rise over preindustrial temperatures – a threshold most scientists say we should avoid – but it hasn’t shown up on the thermometer yet.

We may not be able to predict exactly how much future temperatures or sea levels will rise, but we do know that unless we curb our carbon emissions, our planet will be a very uncomfortable place for our grandchildren and their grandchildren. Large-scale social changes take time: they are the sum of many individual changes, in both attitudes and behaviors. To minimize that time lag, we need to start acting now.   https://theconversation.com/curbing-climate-change-why-its-so-hard-to-act-in-time-80117

Advertisements

August 19, 2017 - Posted by | 2 WORLD, climate change

No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: