ROME — Pope Francis on Thursday greeted the Vatican's diplomatic corps, spoke generally about the hope that comes with any new year, and then got straight to the daunting point.

“The new year,” Francis said, “does not seem to be marked by encouraging signs.”

While saying that maintaining hope is essential, the pope spent the next 45 minutes talking about wars and could-be wars, exploitation, sexual abuse, Internet hate speech, international indifference to humanitarian crises, and the depressing state of the world’s fight against climate change.

He called heightened tensions between the United States and Iran “particularly troubling,” but his remarks amounted to a laundry list of flash points, both major and obscure, from Burkina Faso to Venezuela to Australia.

“Certainly, hope has to be realistic,” Francis said. “It demands acknowledging the many troubling issues confronting our world and the challenges lurking on the horizon. It requires that problems be called by their name and the courage be found to resolve them.”

Francis’s annual speech, delivered in a frescoed Vatican hall, tends to serve as a guidebook for the pope’s worldview, making clear what issues he thinks are most important. In his seventh year as leader of the Roman Catholic Church, Francis’s own reputation has been bruised by the institution’s struggles to combat sexual abuse.

In the meantime, he has sometimes felt like a lonely voice among world leaders, making a case about the responsibility to care for migrants and about the urgent dangers that global warming poses.

Speaking about U.S.-Iran tensions, the pontiff urged dialogue and worried about how recent developments might be “compromising the gradual process of rebuilding in Iraq.”

He said the tensions, which have diminished slightly this week after both countries stepped back from escalation, could set off a “vaster conflict that all of us would want to avert.”

Francis talked about the church’s abuse crisis, pledging that the Vatican is committed to reforms, while calling abuse a crime that damages victims physically and psychologically.

But Francis spoke about youths in general at much greater length than he spoke about abuse, describing how young people look to adults for an example but also “have much to offer” themselves. He then lauded the increasingly forceful role of young people in bringing attention to climate change — and protesting politicians’ inaction.

“The protection of the home given to us by the Creator cannot be neglected or reduced to an elitist concern,” Francis said. “Young people are telling us that this cannot be the case.”

The pope called last month’s United Nations climate conference, which ended with finger-pointing and no meaningful breakthroughs, a dispiriting sign about the willingness of leaders to take significant steps.

“The response to the problems raised by global issues such as climate change remains very weak and a source of grave concern,” he said.

Francis said that a more robust international response is “most urgent” in the Middle East and in the Mediterranean, the deadliest area in the world for migrants. He said that the humanitarian crisis in Yemen is being met by “general indifference,” and that a “pall of silence” risks falling over Syria, where war has been waged for years. The pope also highlighted the “intensification of violence” in Libya, and the way in which the country had become a fertile terrain for the extortion of migrants, who are commonly subjected to sexual violence and torture.

Francis said that “many thousands of people in our world present legitimate requests for asylum, and have verifiable humanitarian needs and a need for protection that are not adequately identified.”

“Many are risking their lives in perilous journeys by land and, above all, by sea,” the pope said. “It is painful to acknowledge that the Mediterranean Sea continues to be a vast cemetery. Consequently, it is increasingly urgent that all states accept responsibility for finding lasting solutions.”