Tag Archives: greenhouse gas emissions

world energy mix

Shortfall in International GHG Pledges

There is a shortfall between the pledges that the nearly 200 countries independently, and internationally as a whole, have made at the COP 21 in Paris last November, compared to the reality of what the planet has in its future. There is also a genuine effort to limit global temperature rise to 2 degree celsius average global temperature increase above the normal numbers (using historical numbers as a baseline for comparison) by the end of this century – the number that represents saving the planet from the worst effects of climate change.

In order to prevent the most damaging effects of climate change, the international community has pledged, in Paris, to increase the use of such sustainability technologies as renewable energy and energy efficiency measures, while decreasing fossil fuel use, in order to mitigate GHG (greenhouse gas) emissions…emissions which lead to global temperature rise. The idea is to keep global temperature rise to under 2 degrees celsius above normal (compared to historical values) by the end of this century.

scoreboard banner: result of international climate change action

The reality is that the average global temperature rise will be significantly greater than what was promised at Paris. A 5-8+ degrees fahrenheit rise in average temperature would result if the world simply maintains the status quo. The pledges in Paris, as well as actions by nations and private investors before and after COP21, demonstrate a genuine global effort in the research, development and effective use of sustainable technologies and measures. Of course, this is great, but global temperature rise still will be over the global temperature goals committed to in Paris.

In other words, at least 2+ degrees celsius change over the acceptable 2 degrees limit by the end of this century will result, even if all pledges by all countries are actually met. Even in this positive scenario (and the best-case scenario discribed below), as of now, there is still a shortfall – this NYTimes infographic clearly illustrates this problem — http://tinyurl.com/gct333

If all nearly 200 nations keep all of their promises from COP21, temperature rise will be limited to just 0.035°C (0.063°F) annually (best case). Even if every government on the planet that participated not only keeps every Paris promise, reduces all emissions as promised by 2030 (2030 was the year of note discussed in Paris), and shifts no emissions to other countries, but also keeps these emission reductions going throughout the rest of the century, temperature rise will be kept to just 3°C (5.4°F) by the year 2100.

Obama’s Clean Power Plan, his moratorium on drilling for oil in the Atlantic, the U.S.’s 3 year moratorium on building coal mines on federal land, China’s 3 year ban on building new coal mines, and their shutting down of thousands of older coal power plants are all very positive signs. Other promising signs include the U.S.’s increased development and use of renewable energy and energy efficiency technologies (as well as in China, India and much of the developing world). Europe has been leading the way for many years, in many respects, in terms of sustainability technologies. However, optimism, in the face of the undeniable math of climate change which clearly tells us more needs to be done, should be weighed carefully against climate change realities.

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hybrid car charge

The benefits of hybrid cars

hybrid vehicle combines energy from a gasoline engine and an electric motor to increase efficiency. Hybrid automobiles increase MPG compared to standard vehicles (50+ for the vehicles addressed in this article), while lowering CO2 and other greenhouse gas emissions. The benefits of hybrid cars include financial savings even above and beyond the $5000-$6000 in savings on gas (over 5 years) that the cars in this article average. For example, hybrids help to avoid road tolls such as London’s congestion charge. Hybrids typically offer features with advantages over standard cars, such as regenerative braking, electric motor drive/ assist and automatic start/ shutoff.

Regenerative braking refers to energy produced from braking and coasting that’s normally wasted, which is stored in a battery until needed by the motor. During electric motor drive/ assist, the electric motor kicks into gear, providing additional torque for such things as hill climbing, passing or quickly accelerating.  For automatic start/ stop, energy is conserved while idling, as the engine is shut off when the vehicle comes to a stop, and is re-started when the accelerator is pressed.

Whereas a normal hybrid car simply combines an electric motor and a gas engine, a plug-in hybrid can run only on electric power, when charged, and can be recharged without using the gas engine. Plug-in hybrid electric vehicles (PHEV’s) have high capacity batteries, and charge by plugging into the grid, storing enough electricity to significantly reduce gas use.

There are two basic types of plug-in hybrids: extended range electric vehicles and blended plug-in hybrids. Extended range electric vehicles work by having only the electric motor turn the wheels, and can run only on electricity until the gasoline engine is needed to generate electricity to recharge the battery that powers the electric motor (or the gas engine can be eliminated entirely, on short rides). Blended plug-in hybrids work by still having both the gas engine and the electric motor connected to the wheels, both propelling the vehicle most of the time.

Electric vehicles (EV’s) drop the gas engine entirely, becoming much more environmentally friendly. The MPG goes way up, but the cost tends to go up as well, and the driving range goes down. These factors; the MPG, cost and range are tied to how efficient, how much capacity, the battery has. The higher the capacity of the battery, the higher the cost, MPG and range. Although EV’s emit no tailpipe pollutants, it remains important that the source for the energy from the grid that charges the vehicle’s battery remains green (i.e. renewable energy) as well.

Hybrid cars take numerous different forms, including the types mentioned above, and then compete against standard gas cars, flex-fuel vehicles, diesel vehicles, etc… European sales of standard hybrid vehicles have increased, but with roughly half the cars in the EU being more fuel efficient diesel engines, EV’s and plug-ins are the more popular choice. These cars can better compete in the global market, in terms of fuel efficiency.

The global hybrid market is still dominated by Toyota, in particular their Prius line, including the Prius Plug-in. The Prius remains California’s most popular car, as a testament to its global popularity. The Prius gets around 50 MPG, costs $25-30K and has a driving range of 540 miles on a full tank of gas. The plug-in model costs $30-35K and gets 95 MPG running on electricity only or 50 MPG running on both electricity and gas, with a driving range of about 600 miles.

The Tesla Model S and the Nissan Leaf are examples of successful electric vehicles. The Tesla Model S with a 60 kW-hr battery pack gets up to 102 MPG’s, costs around $70K and has a driving range of 208 miles on a fully charged battery. The Nissan Leaf costs $30-35K, can get 80 miles on a full charge and hits 128 MPG’s.

(*All figures are as of 2015.)