Weather Patterns / Climate Change

[anjou]

Not wishing to start a war of words over the politics of climate change, how do you see the changing climate affecting live afloat?

Apart from the obvious rise in hurricanes and the eventual rise in sea levels, all beit only a meter or so, and certainly not in my lifetime, what other situations/events do you forsee or have you noticed?

[bewitched]

I've noticed a lateness in the seasons - typhoons here are later - and stronger it seems - particularly bad typhoons in the Philippines this year. Also seasonal currents seem to be later - 2 years ago I noticed that the northbound current inside Palawan was going south in July (it should have been going north for at least 3 months by then).

I can't predict where this will lead, I don't believe anyone has a real handle on what will happen. Predictions seem to range from a small variation in climate in some areas to the apocalyptic "the arctic ice sheet melts, there is no annual discharge of cold water into the North Atlantic and so the ocean currents stop and an ice age ensues"

[anjou]

Life is and must be a cycle, Yin and Yang etc, one action must be ballanced by or cause an equal and opposite reaction.

Therefore, if the Atlantic conveyor current slows or stops because there is insufficient cold glacial melt entering the sea in the far north, then it follows that the warm water return cannot keep the northern waters warm and surely, that will lead to enough cooling of land mass to enable glaciers to reform?

Eastern Europe is on a latitude equal to Newfoundland, Calgary and Vancover. Without the warm gulf waters, our balmy, blighty climate will be dominated by pack ice.
Does it also mean the Carib will be constantly storm blown? Will the Med be a desert by summer and Tundra in winter?

WHat about other parts of the world where there isnt a conveyor current. WHat might the effects be there?

[GordMay]

It's difficult to predict what would happen if the "Conveyor" shut down, because the Arctic and North Atlantic are very complex systems with many interactions between the land, the sea, and the atmosphere. Earth’s complex and dynamic climate system has more than one mode of operation, and each mode produces different climate patterns.

The evidence shows that Earth’s climate system has sensitive thresholds. Pushed past a threshold, the system can jump quickly from one stable operating mode, to a completely different one.

Some scientists worry that melting Arctic sea ice will dump enough (more, not less) freshwater into the North Atlantic to interfere with sea currents*. Some freshwater would come from the ice-melt itself, but the main contributor would be increased rain and snow in the region. Retreating ice cover exposes more of the ocean surface, allowing more moisture to evaporate into the atmosphere and leading to more precipitation.

* Atlantic Meridional Overturning Current, or "Great Ocean Conveyor"

Because saltwater is denser and heavier than freshwater, this "freshening" of the North Atlantic would make the surface layers more buoyant. That's a problem because the surface water needs to sink to drive the primary ocean circulation pattern. Sunken water flows south along the ocean floor toward the equator, while warm surface waters from tropical latitudes flow north to replace the water that sank, thus keeping the Conveyor slowly circulating. An increase in freshwater could prevent this sinking of North Atlantic surface waters, slowing or stopping the circulation.

See also Thermohaline circulation
➥ http://www.google.ca/search?q=Atlant...ient=firefox-a

[Lodesman]

Originally Posted by anjou

Eastern Europe is on a latitude equal to Newfoundland, Calgary and Vancover. Without the warm gulf waters, our balmy, blighty climate will be dominated by pack ice.

Vancouver doesn't have pack ice. Despite the lack of a Pacific "Gulf Stream", Vancouver's climate is very British.

And despite what the IPCC would have you believe, I don't think there has been an increase in the number of hurricanes; nor does their former hurricane expert.

[anjou]

Does the Pacific coast current flow north and supply Vancouver with warmer water?
Im sure 2009 saw a record amount of Carib tornados

[jkleins]

One thing that is effecting sailors is the longer opening of the Northwest Passage. I think I read a record number of crossings this year. It could open up a whole new cruising ground for the adventurous (and cold tolerant).

Jim

[GordMay]

Originally Posted by Lodesman

... And despite what the IPCC would have you believe, I don't think there has been an increase in the number of hurricanes; nor does their former hurricane expert.

You seem to be willing to dismiss a comprehensive assessment report about climate change (IPCC “AR4 Synthesis Report, 2007"), produced by 620 authors and editors from 40 countries, and reviewing most of the science and research on the subject, and which states, in part:
~ There is no clear trend in the number of hurricanes.
~ It is more likely than not (>50%) that there has been some human contribution to the increases in hurricane intensity.
~ It is likely (>66%) that we will see increases in hurricane intensity during the 21st century.

... because you haven’t noted any increase in hurricane activity.
Curious.

[Lodesman]

Originally Posted by anjou

Does the Pacific coast current flow north and supply Vancouver with warmer water?
Im sure 2009 saw a record amount of Carib tornados

No. The Pacific drift, which is the easterly flow of water diverges at Vancouver Island into the north-flowing Alaska current and the south-flowing California current. When the water gets to Alaska, it's considered warm, but the California current is considered a cold current. At 49°N the water is cold.

I don't know what a Carib tornado is - is it like a waterspout?
Seriously, do you have statistics on that? Tornadoes are a localized weather phenomenon which aren't necessarily tied to hurricanes, imo.
You can read a bit on the hurricane controversy here: Are Category 4 and 5 hurricanes increasing in number? : Weather Underground

[Lodesman]

Gord,

Do you know who Christopher Landsea is? Suggest you google him for some interesting reading.

[bobsadler]

and the aussies a reporting no significant change in tropical storms in their neck of the woods:
Research by climate experts has surprising results | The Courier-Mail

of course i work for oil companies (but then guess who else has worked for oil companies and still gets funding from them Pachauri in a spot as climategate hits TERI: India Today - Latest Breaking News from India, World, Business, Cricket, Sports, Bollywood. )

[anjou]

Originally Posted by Lodesman

No. The Pacific drift, which is the easterly flow of water diverges at Vancouver Island into the north-flowing Alaska current and the south-flowing California current. When the water gets to Alaska, it's considered warm, but the California current is considered a cold current. At 49°N the water is cold.

I don't know what a Carib tornado is - is it like a waterspout?
Seriously, do you have statistics on that? Tornadoes are a localized weather phenomenon which aren't necessarily tied to hurricanes, imo.
You can read a bit on the hurricane controversy here: Are Category 4 and 5 hurricanes increasing in number? : Weather Underground

Whats in a name? They are all destructive forces of nature.
The Uk sees a huge amount of tornados but never of the size seen in the USA. With mid atlantic waters warming, there will be more Carib and US bound storms

[sneuman]

Originally Posted by bewitched

I've noticed a lateness in the seasons - typhoons here are later - and stronger it seems - particularly bad typhoons in the Philippines this year. Also seasonal currents seem to be later - 2 years ago I noticed that the northbound current inside Palawan was going south in July (it should have been going north for at least 3 months by then).

I can't predict where this will lead, I don't believe anyone has a real handle on what will happen. Predictions seem to range from a small variation in climate in some areas to the apocalyptic "the arctic ice sheet melts, there is no annual discharge of cold water into the North Atlantic and so the ocean currents stop and an ice age ensues"

I concur on this. When I lived in S.E. Asia until a few years ago, typhoon season seem to be extended, with very powerful typhoons in Philippines not uncommon in December. To give you an idea, the official end of typhoon season in the region is/was Oct. 31.

[GordMay]

Originally Posted by Lodesman

Gord,
Do you know who Christopher Landsea is?

Yes.
Christopher Landsea was a Contributing Author for both the IPCC in 1995 and 2000, but withdrew from his participation in the IPCC Fourth Assessment Report. Landsea claimed the IPCC had become politicized and the leadership ignored his concerns.
Landsea published a study which argued that rising greenhouse gas levels will not influence the intensity of hurricanes in the Atlantic basin.

There are three terms generally used to describe a hurricane season: frequency, intensity and activity.
Hurricane frequency refers to the number of hurricanes that occur.
Hurricane intensity is a measure of the strength or maximum wind speed of a hurricane (the category).
Hurricane activity is the term used by the National Hurricane Center that encompasses both the frequency and intensity of hurricanes in a season.

Globally (not just in the North Atlantic), there are an average of about 90 tropical storms every year. According to IPCC-AR4, globally "there is no clear trend in the annual numbers (frequency) of tropical cyclones."

However, in the North Atlantic, there has been a clear increase in the frequency of tropical storms and major hurricanes. From 1850-1990, the long-term average number of tropical storms was about 10, including about 5 hurricanes. For the period of 1998-2007, the average is about 15 tropical storms per year, including about 8 hurricanes. This increase in frequency correlates strongly with the rise in North Atlantic sea surface temperature, and recent peer-reviewed scientific studies link this temperature increase to global warming.

There is an ongoing scientific debate about the link between increased North Atlantic hurricane activity and global warming. The 2007 report of the IPCC rates the probability of such a link as “more likely than not.” Landsea disagrees.

Hurricane Frequency Is Up But Not Their Strength, Say Researchers
➥ Hurricane Frequency Is Up But Not Their Strength, Say Researchers

Simulated reduction in Atlantic hurricane frequency under 21ST Century warming conditions
➥ Simulated reduction in Atlantic hurricane frequency under twenty-first-century warming conditions : Abstract : Nature Geoscience

[bobsadler]

From NOAA: "A team of scientists have found that the economic damages from hurricanes have increased in the U.S. over time due to greater population, infrastructure, and wealth on the U.S. coastlines, and not to any spike in the number or intensity of hurricanes."

NOAA - National Oceanic and Atmospheric Administration - Increased Hurricane Losses Due to More People, Wealth Along Coastlines, Not Stronger Storms, New Study Says