A common declaration of Pope Francis and Patriarch Bartholomew on the issues of ecology and poverty would be natural is foreseeable for the future, a theological advisor of the Ecumenical Patriarchate of Costantinople told CNA Nov. 28.

"Today, there is no excuse for indifference or inaction. A joint response between Pope Francis and Ecumenical Patriarch Bartholomew can prove both powerful and permanent," said Fr. John Chrissavgis, who works for the partriarch of the Eastern Orthodox Churches.

Fr. Chryssavgis spoke on the eve of Pope Francis' voyage to Turkey, scheduled Nov. 28-30.

During Pope Francis' Nov. 28-30 trip to Turkey, he will meet with Patriarch Bartholomew for an ecumenical prayer on Saturday night at the Phanar, the Headquarters of the Ecumenical Patriarchate in Istanbul.

According to Fr. Chryssavgis, there are thre three main challenges that both the Papacy and the Ecumenical Patriarchate can face together.

First, both should foster "a sense of humility and repentance for the arrogant suspicion and hostile polemics of the past. We should no longer be tempted by isolationism and fanaticism that characterized relations between the two Churches in previous centuries."

Second, "we should honestly examine the theological differences that continue to separate us, especially the issue of authority and primacy, as well as infallibility and collegiality. Pope Francis has already demonstrated his willingness and openness to explore the common tradition of the early, undivided Church on these matters."

And finally – Fr. Chryssavgis maintained – "even as we discuss doctrinal matters, we should not ignore the global problems facing people everywhere, including poverty, war, injustice, and the ecological crisis."

Pope Francis has proven to be very attentive to ecological matters: he already announced he will issue an encyclical on ecology by the beginning of the next year, and often mentioned the notion of human ecology in his speeches – the last time Nov. 25, speaking in front of the European Parliament in Strasbourg.

"The Pope's love of the poor and vulnerable in society makes him equally sensitive to the natural environment," said Fr. Chryssavgis.

On the other hand, Patriarch Bartholomew has "worked tirelessly for the awakening of people's conscience about climate change. Hence the title that he has been given by journalists: 'the Green Patriarch."

Fr. Chryssavgis noted that "it is true that natural and human ecology are inseparably linked. The way we treat people, and especially the poor, is directly reflected in the way we respond to environmental issues; and the way we respect God's creation is manifested in our attitude toward human beings created in the image of God. Indeed, both visionary leaders can discern this truth."

"It would be wonderful – and natural – for the Pope and the Patriarch to stand together on this issue and sign a common declaration, just as Patriarch Bartholomew co-signed the Venice Declaration with Pope John Paul II in 2002. I can certainly foresee this happening in the near future."