As the world’s business, political and media elite made their annual trek to the Swiss town of Davos -– blanketed in more snow than I have seen there for a decade -– conventional wisdom had it they should have all the lightheartedness of a gray, winter, Alpine sky. The Eurozone crisis, the difficulty of getting tough political decisions in the United States, and worries in some of the champions among emerging markets – the chance of a property crash in China, for example, or of runaway inflation in India –- were all said to contribute to a note of pessimism among Davos devotees.

But even if you think that the prophets of global economic doom and gloom are right –- I don’t, as it happens, but that’s another story – there are plenty of reasons to be cheerful about the state of the world. Some of them were collected in Bill Gates’s annual letter on the work of the Bill and Melinda Gates Foundation, which should be required reading for the Davos crowd. The letter detailed some of the extraordinary advances that have been made in global health, for example, over the past decades, with the roll out of vaccines on a massive scale, tremendous progress, especially in India, on the eradication of polio, and, indeed, on the treatment and prevention of HIV/AIDS. I was particularly pleased that Bill’s letter made mention of the rotavirus vaccine that GAVI is rolling out to tackle one of the leading causes of diarrhea – an appalling killer of children, and one which has rarely gotten the public or political dissension that it deserves.

Of course, the letter pointed out how much more needed to be done so that all people, everywhere, could live lives of equal dignity. More funding needs to be devoted to research and development in agriculture –- a key goal of ONE this year. Those of us who advocate for increased resources to go to the world’s poor appreciate that in tough economic times, we have our work cut out for us. But when generous funders like the Gates Foundation and taxpayers around the world have done so much to combat extreme poverty and preventable disease in the last ten years, now would be the very worst moment to give up the fight. That fight is more likely to be won, as Bill pointed out in a passage on the need for more resources for The Global Fund to Fight AIDS, Tuberculosis and Malaria that is worth quoting at length, if citizens in the rich world understood just how much could be done with comparatively few resources.

“Between 2011 and 2013, assuming that all donors honor their commitments, the Global Fund will disburse $10 billion. This is a $2 billion increase, but not nearly the $12–$14 billion that is needed and was hoped for. Citizens of donor countries should know about the difference their generosity has made. The cost of keeping a patient on AIDS drugs has been coming down, and it looks like getting it to $300 per patient per year should be achievable. That will mean every $300 that governments invest in the Global Fund will put another person on treatment for a year. Every $300 that’s not forthcoming will represent a person taken off treatment. That’s a very clear choice. I believe that if people understood the choice, they would ask their government to save more lives.”

My job is to learn about global health and development — and to travel to poor countries to meet farmers who can’t grow enough food, mothers who can’t keep children healthy, and heroes in the field who are doing something about those emergencies. Very few people can devote the time to really understand these complex problems. Even fewer can actually meet the people who are struggling to overcome them. That is why I write an annual letter every year.

I want people to know about the amazing progress we’ve made. I also want them to see how much more progress it will take before we live in a truly equitable world.

In this year’s letter, I focus on food and agriculture (though I also provide updates about all the global health and U.S. education work we do). When I was in high school, a popular book called The Population Bomb painted a nightmarish vision of mass starvation on a planet that has outgrown its carrying capacity. That prediction was wrong, in large part because researchers developed much more productive seeds and other tools that helped poor farmers in many parts of the world multiply their yields. As a result, the percentage of people in extreme poverty has been cut in half in my lifetime. That’s the amazing progress part of the story, and not enough people know it.

But there’s the progress-yet-to-come part, and people need to know that, too. There are still more than 1 billion people who live in extreme poverty. They are located primarily in South Asia and sub-Saharan Africa, and they live on the edge of starvation. There is an irony in this, because most of them are farmers. We can help these 1 billion achieve self-sufficiency, just like we helped billions before them, but we stopped trying. At a certain point, the sense of crisis around food dissipated, and the proportion of foreign aid dedicated to agriculture dropped from one-fifth to less than one-twentieth.

My hope for my annual letter is that it helps people connect to the choice we all have to make. Relatively small investments changed the future for hundreds of millions of small farm families. The choice now is this: Do we continue those investments so that the 1 billion people who remain poor benefit? Or do we tolerate a world in which one in seven people is undernourished, stunted, and in danger of starving to death?

In times of tight budgets, we have to pick our priorities. It’s clear that in this particular time, we’re in danger of deciding that aid to the poorest is not one of them. I am confident, however, that if people understand what their aid has already accomplished—and its potential to accomplish so much more—they’ll insist on doing more, not less. That is why I wrote my letter. I hope you’ll take the time to read it and share it with your friends and family.

I’ve invited students from around the world to write their own annual letters too. You can send your letter, or any questions you have for me, to annualletter@gatesfoundation.org. I’ll be answering and talking about the ideas in your letters in a live webcast on February 2 on my Facebook page.

In his report, he makes the case for why we must continue investing in the livelihoods of poor people—and he suggests some innovative ways to do it.

In the report, Bill Gates says:

“Leadership from the G20 is critically important right now. The global economic situation is as fragile as it has been at any time in the past 50 years. As leaders of the G20, you face a difficult challenge: How do you resolve the immediate crisis while continuing to make smart investments in long-term growth and improved living conditions?

In the past 50 years, a billion people were saved from starvation by advances in agriculture. Health has improved in stunning ways, thanks to innovations like vaccines. In 1960, 20 million children under the age of 5 died. In 2010, fewer than 8 million children under 5 died. The world population more than doubled during this time, which means the rate of death has been cut by over 80 percent. Aid generosity has played an important role in these successes

Despite the current economic crisis, I am optimistic that we can build on the generosity and innovations that worked in the past. The group of countries able to contribute resources to development is larger than ever before. The number of people who can spur innovations is much greater than in the past. For these reasons, I am convinced we can create a new era in development.”

You can download a full copy of the report 21st Century Development: Innovation with impact from the Gates Foundation website.

Ever since the big news last week, our ONE members have been thank yous from some pretty great people: GAVI’s CEO Helen Evans (listen to her message here), USAID Administrator Raj Shah (see his video here) and ONE’s Executive Director Jamie Drummond. Even the White House gave you guys a little nod in a blog post last week.

I’m excited to tell you that we have another person to add to this list: Bill Gates. This morning, Mr. Gates sent a thank you email to all the ONE members who made a big push to support funding for life-saving childhood vaccines.

“The ONE Campaign was a big part of this success. I want to thank you for your help in achieving this incredible milestone. Your calls, tweets, and letters made a real difference—and because of your efforts, GAVI estimates that 4 million lives will be saved in the next five years,” he said in the email.

And in case you missed the news, read this great round-upon donors’ commitments to GAVI for yourself!

How to sum up the last three days in Europe?

Stamina.

Not mine, but Bill Gates’… It’s unreal. He flew in overnight on Sunday, and in just two and a half days travelled to three cities, delivered three powerful Living Proof presentations, lobbied Presidents, Chancellors, and Ministers, gave numerous media interviews and rallied activists. He is a testament to the ability of a committed person to change the world. Of course, he has a few more resources at his disposal than most – but all the more impressive to think he could just be sat on a yacht sipping down piña coladas.

As I expect he himself would say however, Bill Gates isn’t what the trip should be about. What’s important is the impact, did we make a difference? Well, there have already been impressive outcomes from this visit, including Germany and the European Commission pledging to increase their funding for vital vaccines. This extra support will save thousands of children’s lives and free up health systems in developing countries to build healthier, more productive communities.

However, the news yesterday on broken promises shows us how fragile our gains can be and reminds me why this is just the start of our Living Proof campaign…

So, if there is one thing you do today please pass on some Living Proof to a friend, colleague, politician, or loved one (you can find plenty of food for thought on our new website), or simply use the widget below, and encourage them to do the same.

As my grandmother always said you catch more bees with honey than you do with vinegar…

First stop was the European Parliament’s Development Committee, where Bill Gates answered questions from Members of the European Parliament on everything from investing in agriculture, why child vaccines are good for climate change (they will help reduce population numbers as better life expectancy leads families to have less children) to programmes for hand washing to improve sanitation.

Watch the video of Bill’s presentation and the questions and answers here [click on the 'Language' link on the video to select your chosen language]:

Jerzy Buzek, President of the European Parliament, and Bill Gates posted a joint tweet on Living Proof, and Bill’s meetings with European Commissioners covered how environmental policy can contribute to development through green growth, how research and development can invest in more health and agriculture, and how more trade and more aid are needed for development to work.

Development Commissioner Piebalgs and President Barroso endorsed the vital work of the Global Alliance for Vaccines and Immunisations (GAVI), and Barroso stated that 33% of the 1 billion Euros he committed to the Millennium Development Goals (MDGs) last September will be dedicated to the health MDGs, and also committed to increasing the European Commission’s contribution to GAVI at the June pledging conference in London. Very positive!

We’ll be working with ONE Members to make sure those promises become reality , but we were assured that when the Commission commits, it delivers, and we’re very much looking forward to the next 7-year budget to make sure that development remains a priority.

Today the Living Proof campaign moves to Germany, so the baton passes from Strasbourg to Berlin. Onwards!

Last night ONE hosted a Living Proof event in Paris event aimed at convincing French politicians that development is worth their investment, and that they should stick to their promise of reaching 0.7% of Gross National Income on development assistance by 2015.

As I mentioned in my first blog in this series, if Living Proof is to succeed it needs to touch both the head and the heart. Bill Gates and prominent economist Esther Dufflo both made powerful arguments – one of the most interesting was about whether by saving lives we contribute to overpopulation. Bill himself had questioned this when he first got in to development work and after researching the issue came up with some surprising findings.

He found evidence to support the view that when families know their children have a better chance of surviving they choose to have fewer children. This was illustrated on a visual by the graphical and global health guru Hans Rosling (see his TED Talks), which you can see here in an earlier presentation:

You’ll see that as life expectancy goes up, family size goes down…

And so to matters of the heart…If a good hour of facts and figures hadn’t won you over then cue Mamadou Touré a softly spoken man from Cameroon and head of the Africa 2.0 initiative (which mobilizes young African leaders to create change from within). Mamadou stood up to ask a question, and as he did explained that part of the reason he was there and creating his own change was thanks to the opportunities afforded to him thanks in part to aid – he said he himself was ‘Living Proof’.

Sometimes it’s the unexpected things that are the most powerful.

As a ONE member, you can never be sure what you’ll be doing in the name of fighting extreme poverty — it can have some funny twists. One day you might be calling your government to stop proposed budget cuts and the next you might be working with Bill Gates in Paris to promote action on vaccines. Ok, it doesn’t happen THAT often, but for a few of our French members today, that was their experience…

We met up this very bracing Monday morning at the Trocadero in Paris. ONE members were there to support Bill Gates in the first of a series artwork unveilings taking place over the next few days in Europe, and to get the message out. They also attempted to hold back the photographers fighting for the best spot (note to self: brush up on karate skills and never wear ballet flats to such events…).

Bill Gates used the unveiling to stress the need to finally put an end to Polio. For many of us it might come as a surprise that this disease still exists -– in fact, since 1988, this vaccine, which only costs 13 cents, has been provided to billions of children and the number of cases is down more than 99%. But as with smallpox, they key is to eradicate this disease completely so that it can’t keep coming back. 13 cents to save a life… It gives me some perspective…I don’t think anyone can argue with that as a good investment.

Tonight is different again — an event with French politicians to persuade them their investments are worth it…

More to come.

My third annual letter came out recently. One of the major themes of the letter is the miracle of vaccines. Last year, Melinda and I announced that we were working together with partners to make this the Decade of Vaccines, and I wanted to use this year’s letter to explain why.

In particular, my letter focuses on the vaccine for polio, since it’s helped the world get to the threshold of something amazing: eradicating the disease altogether. We’re incredibly close and we need to finish the job.

We put together a video, called “Vaccines Save Lives,” to try to describe why vaccines are a miracle in a vivid way. I hope you enjoy it—and share it with your friends.

This year, the focus is on vaccines — particularly the polio vaccine — as well as HIV/AIDS, malaria, agriculture and education. You can download an electronic copy on the Gates Foundation website, but to get you started, here’s a list of important points Gates makes in his letter:

1. Until polio is wiped out completely, the disease is still very much alive. The money that we will save by eradication will far exceed what we are spending on efforts now — it could save the world up to $50 billion over the next 25 years!

2. Vaccines are the most effective and cost-effective health tool invented. If we simply scale up existing vaccines in the five countries with the highest child mortality, we could save 3 million lives (not to mention more than $2.9 billion in treatment costs alone) over the next decade.

3. The fight against malaria is making huge strides. Of the 99 countries with the disease, 43 have decreased cases of the disease by more than 50 percent!

4. Bed nets can have a huge impact on the fight against malaria. Many amazing grassroots groups are helping by delivering bed nets. The Nothing But Nets campaign has recruited hundreds of thousands of individuals, as well as organizations like the United Methodist Church and National Basketball Association involved in the fight against malaria.

5. Neonatal deaths can be reduced by over 50 percent by increasing the number of births done by a skilled provider in a clinic and educating mothers on sanitary measures and proper child nutrition.

6. Although progress continues, the pace is still slow in fighting the AIDS epidemic. There are two fronts of this war that need to be tackled: treating those already infected and preventing new infections.

7. More attention needs to be given to agricultural development, since most poor people in the world feed their families and earn their living from farming. It has been proven that when farmers increase productivity, nutrition improves and hunger and poverty are reduced.

As Gates rightfully states, “Securing the conditions that will lead to a healthy, prosperous future for everyone is a goal I believe we all share.” We’re excited for the great strides The Bill and Melinda Gates Foundation will make in 2011!