Atmospheric

A study sheds new light on how the tilt of the Earth affects the world's heaviest rainbelt and ths the climate overall. Data from the past 282,000 years shows a connection between the Earth's tilt, called obliquity, that shifts every 41,000 years, and that the movement of a low pressure band of clouds that is the Earth's largest source of heat and moisture -- the Intertropical Convergence Zone.


The climate is complex and nothing shows that more than when numerical models are forced to stop predicting the past and have to actually project what could happen in the future.

But the past can at least inform if models are really wrong and an analysis of fossil corals and mollusk shells from the Pacific Ocean reveals there is no link between the strength of seasonal differences and El Niño, a complex but irregular climate pattern with large impacts on weather - but the top nine climate models in use today simplistically associate exceptionally hot summers and cold winters with weak El Niños, and vice versa.


Not much is predictable about climate, despite assurances by politicians and activists meeting in Paris, and one claim that global warming skeptics use - that more CO2 is good for plants - is also correct but also not predictable.

Instead, inter-annual variation in climate has stronger effects on predators such as spiders than populations of their detritivorous prey, such as isopods, which could lead to changes in food chain length, which can in turn influence decomposition and plant growth. These findings emphasize the importance of combined approaches that consider food webs and physiological processes to understand the consequences of global climate change.


Most climate models overestimate the increase in global precipitation due to climate change, according to an analysus of over 25 models and found they underestimate the increase in absorption of sunlight by water vapor as the atmosphere becomes moister, and therefore overestimate increases in global precipitation.

The team found global precipitation increase per degree of global warming at the end of the 21st century may be about 40 percent less than what the models, on average, currently predict. 


Carbon dioxide emissions have always been something of a guess because they rely on self-reported figures. The developed world has been transparent but it was only a few years ago that China admitted to under-counting its own emissions, telling a different tale than the pollution clouds that wafted into other countries did.


After a decade of rapid growth in global CO2 emissions, spurred on by increases in China which offset declines in the US and Europe thanks to natural gas, increases have leveled off: 2012 saw only 0.8%, 2013 was 1.5% and 2014 was 0.5%. Last year, the world's economy continued to grow by 3% overall and even China's unrelenting emissions were held in check.

To some, that means the decoupling of CO2 emissions from global economic growth. To others, it signals that the developed world has given up on manufacturing. Instead, a country like India can increase its emissions by 7.8% and became the fourth largest emitter globally while claiming the same developing nation status China and Mexico do.


Ancient climates on Earth may have been more sensitive to carbon dioxide than was previously thought, according to an analysis of nahcolite crystals found in Colorado's Green River Formation, formed 50 million years old during a hothouse climate.

Scientists found that CO2 levels during this time may have been as low as 680 parts per million (ppm), nearly half the 1,125 ppm predicted by previous experiments. The new data suggests that past predictions significantly underestimate the impact of greenhouse warming and that Earth's climate may be more sensitive to increased carbon dioxide than was once thought


The rainwater that fell in some of the villages of Zamora, Spain last autumn brought along a green microalgae that turns a reddish color when in a state of stress.  Blood rain. It is not an isolated phenomenon.  Kerala, India got a blood rain in the summer of 2001 and since then so has the southern part of the country and Sri Lanka. Scientific studies have confirmed that the algae Trentepohlia was responsible for those events. 


The long history of severe droughts across Europe and the Mediterranean has largely been told through historical documents and ancient journals but an atlas based on scientific evidence uses tree rings to map the reach and severity of dry and wet periods across Europe, parts of North Africa and the Middle East, year to year over the past 2,000 years.

The Old World Drought Atlas significantly adds to the historical picture of long-term climate variability over the Northern Hemisphere. In so doing, it should help climate scientists pinpoint causes of drought and extreme rainfall in the past, and identify patterns that could lead to better climate model projections for the future. 


Mars doesn't have much in the way of Earth-like weather, it does evidently share one kind of weird meteorology: acid fog. 

Astronomer Shoshanna Cole of Ithaca College gathered data from instruments on the 2003 Mars Exploration Rover Spirit and suggests acidic vapors may have eaten at the rocks in a 100-acre area on Husband Hill in the Columbia Hills of Gusev Crater on Mars. 

The work focused on the 'Watchtower Class' outcrops on Cumberland Ridge and the Husband Hill summit.