“What was life like before the Industrial Revolution?” Hayhoe asked during a keynote address at the Citizens’ Climate Lobby conference in Washington, D.C. “It was short. It was brutal.” A woman’s work was an endless cycle of drudgery. Economies were built on the backs of children and slaves. “So I realized that I am truly and profoundly grateful for the benefits and the blessings that fossil fuels have brought us.”

They were clapping for fossil fuels because it was cathartic to acknowledge that, for all the damage done, coal and gas and oil had been gifts to mankind.

She knows how to speak to oilmen, to Christians, to farmers and ranchers, having lived for years in Lubbock, Tex., with her pastor husband. She is a scientist who thinks that we’ve talked enough about science, that we need to talk more about matters of the heart.

Peru is no promised land. Sand-colored shantytowns mar its cities, and rural life can be backbreaking. A fifth of the population lives in poverty. Yet more than 517,000 Venezuelans have arrived here so far this year, on top of the 100,000 who came in 2017 – making it the region’s second-largest host for Venezuelan migrants after Colombia. As many as 2 million Venezuelans will empty out of their country this year, and more than 1,000 cross the Peruvian border each day.

For them, even Peru is a paradise.

A nation that was once the richest per capita in South America – and one of its best educated — has an estimated poverty rate near 87 percent. Malnutrition and disease are spreading unabated.  Hyperinflation has broken supply chains, putting food and medicine out of reach for millions.

The changes to the agreement with the rebel group, the Revolutionary Armed Forces of Colombia, or the FARC, were announced in Havana and addressed a range of topics — such as where rebels would be confined after disarming and how courts might address drug trafficking offenses — that negotiators said had troubled voters.

The agreement also appeared to withdraw a promise of guaranteed seats for rebels in Congress — one key demand of those who said the rebels would be unfairly rewarded with political positions.

Coffee and milk became luxuries for me a few years ago, but the really scary scarcity — of things like bread and chicken — hit my middle-class home at the beginning of this year. There was a week when I had to brush my teeth with salt.

Nine out of 10 Venezuelans can no longer afford to buy enough food, according to a study by Simón Bolívar University. The I.M.F. has forecast that inflation would exceed 700 percent this year.

We agreed that our best hope, really, is the Organization of American States and its Democratic Charter thing.

If a final accord is signed within six months, as the negotiators have pledged, Colombia would offer an example of hard-won peacemaking at a time when so many other conflicts, which are spawning the largest wave of refugees since World War II, seem intractable.

As of last year, the three-way fight among guerrilla factions, government forces and right-wing paramilitary bands that often acted as proxies for the state, had killed more than 220,000 people and displaced an estimated 5.7 million. At the peak of the conflict, in 2000, kidnappings for ransom surpassed 3,000 a year.

The talks have forced Colombians to take stock of a painful past and face uncomfortable truths. Dozens of victims traveled to Havana to speak about abuses they endured at the hands of guerrilla leaders. Some implicated government forces in brutal acts. When I met some young FARC members in Havana last year during a reporting trip, I came to see them in a new light as they described taking up arms as a desperate choice they were forced to make to survive.

The series of inquiries that ignited the public’s rage were the work of an uncommon alliance of local prosecutors and investigators backed by the United Nations, known as the International Commission Against Impunity in Guatemala or by its Spanish-language acronym, Cicig.

Established in 2007 to help expose the ties between criminal networks and politicians, the commission eventually emboldened the nation’s own prosecutors to hold the elite to account, and become a source of inspiration for many Guatemalans. For much of its history, Guatemalan society has been divided, its different constituencies fighting their battles alone. The nation’s indigenous population, which suffered the most under the civil war, which killed about 200,000 people, has long struggled for equal rights with little success.

Yet the movement that began in April forged an unprecedented alliance of different groups. Guatemala City’s middle class, long reluctant to speak out, began joining forces with peasant and indigenous groups. Eventually, the nation’s church and business leaders also took the side of the protesters to demand change.