Started in Sydney, Australia in 2007, Earth Hour quickly grew into a global observance. More than 1,000 cities in over 80 countries observed Earth Hour 2009 on Saturday March 28th, as homes, office towers and landmarks turned off their lights for an hour starting at 8.30 pm local time to raise awareness about climate change and the threat from rising greenhouse gas emissions. Collected here are a series of before-and-after photographs - which (starting with the second one below) will fade between "on" and "off" when clicked. Let me state that again, since I know not everyone reads the whole intro here - starting with image #2 below, click on the image to see an animated fade between "on" and "off". This effect requires javascript to be enabled. (17 photos total)

The Red River is approaching record flood levels, likely to break century-old records this weekend. Flowing north toward Manitoba along the Minnesota-North Dakota border, the river is jammed up by ice and is being fed by rain, snow and meltwater. The National Weather Service has issued projections of a crest of 43 feet near Fargo, North Dakota, 24 feet above flood stage. Volunteers and national guardsmen are out in force, building levees, rescuing and evacuating those that need to get to higher ground. Cold temperatures are hampering efforts, freezing damp sandbags and making the job that much more strenuous for volunteers. 800 more National Guard troops and 150 Red Cross personnel are arriving in the area this weekend. (30 photos total)

In December of 2006, Mexico's new President Felipe Calderón declared war on the drug cartels, reversing earlier government passiveness. Since then, the government has made some gains, but at a heavy price - gun battles, assasinations, kidnappings, fights between rival cartels, and reprisals have resulted in over 9,500 deaths since December 2006 - over 5,300 killed last year alone. President Barack Obama recently announced extra agents were being deployed to the border and Secretary of State Hillary Clinton heads to Mexico today to pursue a broad diplomatic agenda - overshadowed now by spiraling drug violence and fears of greater cross-border spillover. Officials on both sides of the border are committed to stopping the violence, and stemming the flow of drugs heading north and guns and cash heading south. (34 photos total)

The Northern Hemisphere is once more beginning its lean towards the Sun, with the spring equinox taking place last Friday, March 20th. People all over are welcoming the spring sunshine and new growth in many ways - from Stonehenge and Mayan pyramids to Dutch meadows and Texan beaches. Here is a collection that shows some of the signs of spring as we shake off the last bits of winter. (29 photos total)

On February 28th, a team of four Spanish teenage students and their instructor from IES La Bisbal school in Catalonia launched a weather probe they designed and built themselves. Their helium-filled balloon carried a payload of electronics and a camera to take atmospheric measurements and photographs throughout the trip. After getting permission from aviation officials and getting good weather, they released the probe on a trip that took it over 30,000 meters (19 miles) above sea level, through winds gusting up to 100 kph, and temperatures reaching -54C (-65.2F), and traveling 38 kilometers overland in a time of 2 hours and 10 minutes. The Meteotek08 team has collected their images and data on both their blog and flickr page, and has kindly given me permission to share these photos here with you. (28 photos total)

Scientists sailed out to have a closer look at the eruptions of an undersea volcano off the coast of Tonga in the South Pacific Ocean today. Tonga's head geologist, Kelepi Mafi, said there was no apparent danger to residents of Nuku'alofa and others living on the main island of Tongatapu. Officials also said it may be related to a quake with a magnitude of 4.4 which struck last March 13 around 35 kilometers from the capital at a depth of nearly 150 kilometres. (I know this is an off-day posting, but really, thought the images were worth it - 12 photos total)

The state of our global economy: foreclosures, evictions, bankruptcies, layoffs, abandoned projects, and the people and industries caught in the middle. It can be difficult to capture financial pressures in photographs, but here a few recent glimpses into some of the places and lives affected by what some are calling the "Great Recession".   (edit: After reading some comments about this on Boing Boing, I was able to track down the location of the newspaper boxes in photo #30. The boxes belong to the San Francisco Chronicle, who I called and confirmed that the boxes had been removed per city rules, not due to recession. The photo came across the wire with the caption below, the contextual error was mine.) (35 photos total)

Somali pirates continue their attacks against international ships in and around the Gulf of Aden, despite the deterrent of stepped-up international naval escorts and patrols - and the increased failure rate of their attacks. Under agreements with Somalia, the U.N, and each other, ships belonging to fifteen countries now patrol the area. Somali pirates - who have won themselves nearly $200 million in ransom since early 2008 - are being captured more frequently now, and handed over to authorities in Kenya, Yemen and Somalia for trial. Collected here are some recent photos of piracy off the coast of Somalia, and the international efforts to rein it in. (30 photos total)

Last Wednesday (March 11th), people in India and other countries with large Hindu populations celebrated Holi, the Festival of Colors. Holi is celebrated as a welcoming of Spring, and a celebration of the triumph of good over evil. What that translates to in action is an enthusiastic dropping of inhibitions, as people chase each other and playfully splash colorful paint, powder and water on each other. People also attend bonfires to commemorate the story of Prahlada, a Hindu figure and devout follower of Lord Vishnu who prevailed over his father and the demoness Holika with the power of his devotion. Collected here are photos from this year's Festival of Colors. (27 photos total)

The Sri Lankan Civil War, waged between separatist Tamil rebels and the government of Sri Lanka - a conflict which has run hot and cold over 26 years, and has cost over 70,000 lives - may now be approaching its end. The ethnic Tamil rebel force called The Liberation Tigers of Tamil Eelam (or LTTE, or just "Tamil Tigers") has been fighting for the creation of an independent Tamil state since 1983, using both conventional warfare techniques and terrorist methods. Since 1987, the LTTE has claimed responsibility for nearly 200 suicide attacks, more than any organization in the world. Now, since late 2008, aggressive Sri Lankan government forces have dealt many serious defeats to the LTTE, capturing towns and airfields, and recently trapping the remaining 1,000 (estimated) LTTE rebels in a 37 square km (15 sq m) area, surrounded by 50,000 government troops. Army shelling and retaliation by desperate rebels has led to many recent civilian casualties, and an estimated refugee population of over 200,000. The Sri Lankan government has exercised tight control on media over the years, limiting coverage of the conflict and allegedly inciting its supporters, and several journalists have paid with their lives. (37 photos total)

As winter begins to wind down, we are still in the middle of sled dog racing season. The Iditarod in Alaska had its ceremonial start in Anchorage last Saturday (the 7th), the Yukon Quest race from Canada's Yukon Territory to Alaska took place back in mid-February, and the Can-Am Crown races were held in Maine only a couple of weeks ago. The most well-known of the races, the Iditarod Iditarod Trail Sled Dog Race, covers 1,868 km (1,161 mi), and takes anywhere from 8 to 12 days for mushers and their teams of 16 dogs to complete. Collected here are several photos from recent sled dog races and training sessions around the Northern Hemisphere. (28 photos total)

Last month, Cambodia began a trial for crimes against humanity that took place three decades earlier. The U.N.-backed tribunal has indicted and is now trying five former Khmer Rouge officials for crimes against humanity and war crimes during the years of 1975-79. In that short span, while the Khmer Rouge was in power, an estimated 1.4 million Cambodians died (possibly up to 2 million) due to Khmer policies, which included forced labor, outright executions, starvation, and torture - for an idea of the magnitude, click here for a visualization. All these acts were part of the Khmer Rouge's disastrous effort to dismantle their society and build a communist utopia. Now, 30 years later, Cambodia is still recovering - a young country, with over 50% of the population younger than 25, millions of leftover land mines, extreme poverty and a still-rebuilding agricultural system. Collected here are some recent photos from Cambodia, its people, the tribunal and more. Special thanks to my friend Alicia Conway, currently in Phnom Penh. (28 photos total)

Robotic systems continue to evolve, slowly penetrating many areas of our lives, from manufacturing, medicine and remote exploration to entertainment, security and personal assistance. Developers in Japan are currently building robots to assist the elderly, while NASA develops the next generation of space explorers, and artists are exploring new avenues of entertainment. Collected here are a handful of images of our recent robotic past, and perhaps a glimpse into the near future. (32 photos total)

Late last month, the Parliament of Kyrgyzstan voted - by an overwhelming margin - to terminate their lease to the United States of Manas Air Base, and required the Americans to vacate the base within six months. The vote followed closely on the heels of an earlier announcement that Russia would be providing over $2 billion in financial aid to Kyrgyzstan. Manas is a crucial air base for operations in and around Afghanistan, and U.S. officials remain hopeful that there may still be room for negotiation. The majority of Kyrgyzstan's population appears to have little concern about the closure, instead focusing on their own struggles to get by, as migrant work in Russia has recently evaporated, and jobs at home in Kyrgyzstan are hard to come by. News photos from Kyrgyzstan are few and far between - that said, here is a collection of recent scenes from festivals, rural life, and Manas Air Base in Kyrgyzstan. (25 photos total)