The 2008 winter was among the coldest in 40 years -- for the upper Midwest, the Plains States and much of central Canada.

Madison residents shoveled away a 117-year record snowfall (105 inches-plus) while Eau Claire recorded some 43 days of below-zero temperatures.

The opening of the locks to Mississippi barge traffic, delayed three weeks by ice, was the latest since the modern waterway opened in 1940.

The upper Midwest had an average temperature 6 degrees below normal throughout the month of May. Even the rash of recent severe weather can be traced to incursions from a cold air mass that continues to linger over the northern plains.

Rare snowfalls struck Buenos Aires, Cape Town and Sydney during their mid-year winter, while China continually battled blizzards. Even Baghdad experienced measurable snowfall.

Antarctic pack-ice far exceeded what Captain Cook saw on his 18th-century voyage into the southern Ocean.

Miles-thick ice continues to accumulate on the frozen continent despite peripheral melting along the Antarctic Peninsula and occasional calving of an ice block.

At the opposite pole, floe-ice once again spanned the entire Arctic Ocean and by April had extended into the Bering Strait, making up for the celebrated melt-back.

From January 2007 through January 2008, the average global temperature fell by nearly 1 degree Fahrenheit, based on data obtained by the MET Office in the United Kingdom and other international temperature monitoring networks.

What do we make of this?

A recent climate conference in New York City, sponsored by the Heartland Institute, provides some answers.

More than 100 climatologists in attendance dispelled notions that the global warming debate is over.

Most of the others in attendance (more than 500) would readily acknowledge the existence of post-Little Ice Age warming, but believe man-made emissions are unlikely to cause major climate change and signed a declaration to that effect.

Bill Gray, dean of hurricane forecasters, explained how the deep ocean currents that well up along the western coast of South America account for the comings and goings of the familiar El Nino and La Nina cycles and the longer-phased Pacific Decadal Oscillation. These cycles profoundly affect weather patterns across North America and beyond.

Solar experts at the conference highlighted how sunspots, and associated magnetic storms on the Sun 's surface, also influence Earth 's weather and climate.

The previous (very strong) 11-year sunspot cycle, associated with the recent warmth, ended in 2007, after having peaked in 2002. The new cycle should have already begun, but hasn 't yet.

In the absence of sunspots, solar flares are minimal. Flares eject massive streams of electrons and protons outward from the Sun.

A portion of this stream, called the "solar wind, " bathes our planet, producing the aurora and interfering with communications, and, as it interacts with Earth 's magnetic field, protects us from harmful cosmic radiation.

During periods of weak solar activity -- as at present -- cosmic rays (high-energy protons from interstellar space) penetrate through the troposphere and ionize oxygen and nitrogen molecules.

The ions are nucleating sites for water vapor that condenses into clouds. When sunspots are at a minimum, more clouds form and, correspondingly, more sunlight is reflected back into space. The enhanced reflectance (albedo) cools the Earth.

We all have experienced how quickly the temperature drops when the sun ducks behind a puffy white cloud on a warm, dry afternoon.

Past cool periods are closely correlated with low sunspot numbers (astronomers have kept close tabs on sunspots since Galileo 's time).

Some solar-physicists are now saying if the current cycle doesn 't begin to produce spots soon, we can expect a cool-down like the one in the 19th century known as the "Dalton minimum " -- or worse.

Decades-long cooling in the past brought crop failures to Europe from repeated summer frosts and restricted growing seasons.

With grain shortages already staring us in the face, we 'd be advised to consider what we 'd do in the event of a global cool-down instead of a warming that may or may not continue.

We might consider ways to transform semi-desert into arable land and to develop seed with shorter maturing cycles suitable for a sub-boreal grain belt. If cooling should begin in earnest, we will quickly forget global warming as we face the new challenges ahead.

Balgord is a consultant and runs Environmental & Resources Technology Inc. in Middleton.