IPCC REPORT ON GLOBAL WARMING

IPCC REPORT ON GLOBAL WARMING:

The IPCC is an intergovernmental panel on climate change a group of scientists convened by the united nations to make recommendations to world leaders. Ninety-one leading scientists from 40 countries who together examined more than 6,000 scientific studies. Specialists such as Katharine Mach, who studies new approaches to climate assessment at stanford university; Tor Arve Benjaminsen, a human geographer at the Norwegian university of life sciences; and Raman Sukumar, an ecologist at the indian institute of science.

TITLE OF REPORT: “Global warming of 1.5 °c. An IPCC special report on the impacts of global warming of 1.5 °c above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty”

Scientists who reviewed the 6,000 works referenced in the report, said the change caused by just half a degree came as a revelation. We can see there is a difference and it’s substantial.

At 1.5c the proportion of the global population exposed to water stress could be 50% lower than at 2c, it notes. Food scarcity would be less of a problem and hundreds of millions fewer people, particularly in poor countries, would be at risk of climate-related poverty.

At 2c extremely hot days, such as those experienced in the northern hemisphere this summer, would become more severe and common, increasing heat-related deaths and causing more forest fires.

But the greatest difference would be to nature. Insects, which are vital for pollination of crops, and plants are almost twice as likely to lose half their habitat at 2c compared with 1.5c. Corals would be 99% lost at the higher of the two temperatures, but more than 10% have a chance of surviving if the lower target is reached.

This quote summarizes:

“The IPCC maps out four pathways to achieve 1.5c, with different combinations of land use and technological change. Reforestation is essential to all of them as are shifts to electric transport systems and greater adoption of carbon capture technology.”

~ Jonathan Watts, global environment editor at “The Guardian”

#ipcc #climatechange #actnow #sciencegeek

Greenland Ice Sheet Melt

Greenland Ice Sheet Melt:

Researchers reconstructed the mass balance of the Greenland Ice Sheet by comparing estimates of the amount of ice that has been discharged into the ocean with the accumulation of snowfall in the drainage basins in the country’s interior for the past 46 years. The researchers found that the rate of ice loss has increased sixfold since then — even faster than scientists thought.

Since 1972, ice loss from Greenland alone has added 13.7 millimeters (about half an inch) to the global sea level, the study estimates. The island’s ice sheet is the leading source of water added to the ocean every year. A study published in December that looked at ice core samples found that Greenland’s ice sheets have been melting at an “unprecedented rate” over the past couple decades, about 50% higher than pre-industrial levels and 33% above levels in the 20th century. Greenland’s ice sheets contain enough water to raise global sea levels by 23 feet, research shows.

If this year is any indication, the ice melt trend is sure to continue. The summer melt season has already started in Greenland, according to the National Snow & Ice Data Center — more than a month ahead of schedule. Without serious efforts to curb carbon emissions and slow climate change, ice loss could become a much bigger problem for the country and the world.

Forty percent to 50% of the planet’s population is in cities that are vulnerable to sea rise and is bad news for places like New York, Miami, Los Angeles, Tokyo and Mumbai.

“As glaciers will continue to speed up and ice/snow melt from the top, we can foresee a continuous increase in the rate of mass loss, and a contribution to sea level rise that will continue to increase more rapidly every year.”
~ Eric Rignot, professor of Earth system science at the University of California, Irvine.

Greenland images & Diagrams  included above.

Source: CNN & National Academy of Sciences

Human Driven Climate Change

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There is quite possibly not a more contentious debate going on in America than global warming and its causes. The science is clear with 97% (based on 11,944 abstracts of research papers) of climate scientists worldwide declaring that human influence is the dominant force driving global warming. The consensus position is articulated by the Intergovernmental Panel on Climate Change (IPCC) statement that “human influence has been the dominant cause of the observed warming since the mid-20th century”. The National Academies of Science from 80 countries have issued statements endorsing the consensus position. Nevertheless, the existence of the consensus continues to be questioned.

A dumbed down (i.e. No math) summary of the theory of the Greenhouse effect:

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Energy from the Sun that makes its way to Earth can have trouble finding its way back out to space. The greenhouse effect causes some of this energy to be waylaid in the atmosphere, absorbed and released by greenhouse gases.

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Without the greenhouse effect, Earth’s temperature would be below freezing. It is, in part, a natural process. However, Earth’s greenhouse effect is getting stronger as we add greenhouse gases to the atmosphere. That’s is warming the climate of our planet.

Solar energy absorbed at Earth’s surface is radiated back into the atmosphere as heat. As the heat makes its way through the atmosphere and back out to space, greenhouse gases absorb much of it. Why do greenhouse gases absorb heat? Greenhouse gases are more complex than other gas molecules in the atmosphere, with a structure that can absorb heat. They radiate the heat back to the Earth’s surface, to another greenhouse gas molecule, or out to space.

Even though only a tiny amount of the gases in Earth’s atmosphere are greenhouse gases, they have a huge effect on climate. Sometime during this century, the amount of the greenhouse gas carbon dioxide in the atmosphere is expected to double. Other greenhouse gases like methane and nitrous oxide are increasing as well. The quantity of greenhouse gases is increasing as fossil fuels are burned, releasing the gases and other air pollutants into the atmosphere. Greenhouse gases also make their way to the atmosphere from other sources. Farm animals, for example, release methane gas as they digest food. As cement is made from limestone, it releases carbon dioxide.

With more greenhouse gases in the air, heat passing through on its way out of the atmosphere is more likely to be stopped. The added greenhouse gases absorb the heat. They then radiate this heat. Some of the heat will head away from the Earth, some of it will be absorbed by another greenhouse gas molecule, and some of it will wind up back at the planet’s surface again. With more greenhouse gases, heat will stick around, warming the planet.

What can be done?

“Humans have caused major climate changes to happen already, and we have set in motion more changes still. Even if we stopped emitting greenhouse gases today, global warming would continue to happen for at least several more decades if not centuries. That’s because it takes a while for the planet (for example, the oceans) to respond, and because carbon dioxide – the predominant heat-trapping gas – lingers in the atmosphere for hundreds of years. There is a time lag between what we do and when we feel it.

In the absence of major action to reduce emissions, global temperature is on track to rise by an average of 6 °C (10.8 °F), according to the latest estimates. Some scientists argue a “global disaster” is already unfolding at the poles of the planet; the Arctic, for example, may be ice-free in the summer within just a few years. Yet other experts are concerned about Earth passing one or more “tipping points” – abrupt, perhaps irreversible changes that tip our climate into a new state.

But it may not be too late to avoid or limit some of the worst effects of climate change. Responding to climate change will involve a two-tier approach: 1) “mitigation” – reducing the flow of greenhouse gases into the atmosphere; and 2) “adaptation” – learning to live with, and adapt to, the climate change that has already been set in motion. The key question is: what will our emissions of carbon dioxide and other pollutants be in the years to come? Recycling and driving more fuel-efficient cars are examples of important behavioral change that will help, but they will not be enough. Because climate change is a truly global, complex problem with economic, social, political and moral ramifications, the solution will require both a globally-coordinated response (such as international policies and agreements between countries, a push to cleaner forms of energy) and local efforts on the city- and regional-level (for example, public transport upgrades, energy efficiency improvements, sustainable city planning, etc.). It’s up to us what happens next.”

“Global Climate Change: Evidence.” NASA Global Climate Change and Global Warming: Vital Signs of the Planet. Jet Propulsion Laboratory / National Aeronautics and Space Administration, 15 June 2008. Web. 14 Jan. 2015. .